NL-23-0928, Application to Revise Technical Specifications to Adopt TSTF-584, Eliminate Automatic RWCU System Isolation on SLC Initiation

Application to Revise Technical Specifications to Adopt TSTF-584, Eliminate Automatic RWCU System Isolation on SLC Initiation

ML25108A112
Person / Time
Site:	Hatch
Issue date:	04/18/2025
From:	Coleman J Southern Nuclear Operating Co
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
NL-23-0928
Download: ML25108A112 (1)

Text

Regulatory Affairs 3535 Colonnade Parkway Birmingham, AL 35243 205 992 5000 April 18, 2025 Docket Nos.: 50-321 NL-23-0928 50-366 10 CFR 50.90 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Edwin I. Hatch Nuclear Plant - Units 1 & 2 Application to Revise Technical Specifications to Adopt TSTF-584, "Eliminate Automatic RWCU System Isolation on SLC Initiation" Ladies and Gentlemen:

Pursuant to 10 CFR 50.90, Southern Nuclear Operating Company (SNC) requests a license amendment to the Edwin I. Hatch Nuclear Plant (HNP) Units 1 and 2 Renewed Facility Operating Licenses DPR-57 and NPF-5 respectively.

SNC requests adoption of TSTF 584, "Eliminate Automatic RWCU System Isolation on SLC Initiation." Technical Specification (TS) 3.3.6.1, "Primary Containment Isolation Instrumentation,"

is revised to remove the requirement that the Reactor Water Cleanup (RWCU) System automatically isolate on manual initiation of the Standby Liquid Control (SLC) System. This change to the TS facilitates a future change to the plant design and procedures to require manually isolating the RWCU System when manually initiating the SLC System.

The enclosure provides a description and assessment of the proposed changes. Attachment 1 provides the existing TS pages marked to show the proposed changes. Attachment 2 provides revised (clean) TS pages. Attachment 3 provides the existing TS Bases pages marked to show revised text associated with the proposed TS changes and is provided for information only.

SNC requests that the amendment be reviewed under the Consolidated Line Item Improvement Process (CLIIP). Approval of the proposed amendment is requested within 6 months of acceptance. 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 Georgia State Officials.

U. S. Nuclear Regulatory Commission NL-23-0928 Page 2 This letter contains no NRC commitments. If you have any questions, please contact Ryan Joyce at 205.992.6468.

I declare under penalty of perjury that the foregoing is true and correct. Executed on the 18th day of April 2025.

Respectfully submitted, Jamie M. Coleman Director, Regulatory Affairs Southern Nuclear Operating Company JMC/agq/cbg

Enclosure:

Description and Assessment Attachments: 1. Proposed Technical Specification Changes (Mark-up)

2. Revised Technical Specification Pages

3. Proposed Technical Specification Bases Changes (Mark-up) - For Information Only cc:

Regional Administrator, Region ll NRR Project Manager - Hatch 1 & 2 Senior Resident Inspector - Hatch 1 & 2 Director, Environmental Protection Division - State of Georgia RType: CHA02.004

Edwin I. Hatch Nuclear Plant - Units 1 & 2 Application to Revise Technical Specifications to Adopt TSTF-584, "Eliminate Automatic RWCU System Isolation on SLC Initiation" Enclosure Description and Assessment

Enclosure to NL-23-0928 Description and Assessment E-1

1.0 DESCRIPTION

Southern Nuclear Operating Company (SNC) requests adoption of TSTF 584, "Eliminate Automatic RWCU System Isolation on SLC Initiation," into the Edwin I. Hatch (HNP)

Units 1 and 2 Technical Specifications (TS). TS 3.3.6.1, "Primary Containment Isolation Instrumentation," is revised to remove the requirement that the Reactor Water Cleanup (RWCU) System automatically isolate on manual initiation of the Standby Liquid Control (SLC) System. This change to the TS facilitates a future change to the plant design and procedures to require manually isolating the RWCU System when manually initiating the SLC System.

2.0 ASSESSMENT

2.1 Applicability of Safety Evaluation SNC has reviewed the safety evaluation for TSTF-584 provided to the Technical Specifications Task Force in a letter dated July 31, 2023. This review included a review of the NRC staffs evaluation, as well as the information provided in TSTF-584. SNC has concluded that the justifications presented in TSTF-584 and the safety evaluation prepared by the NRC staff are applicable to HNP Units 1 and 2 and justify this amendment for the incorporation of the changes to the HNP Units 1 and 2 TS.

SNC confirms that the HNP emergency operating procedures only credit manual initiation of the SLC System by the plant operators.

SNC confirms that the HNP response to an anticipated transient without scram (ATWS) event that requires SLC System actuation would also result in automatic isolation of the RWCU system.

2.2 Variations SNC is proposing variations from the TS changes described in TSTF-584 or the applicable parts of the NRC staffs safety evaluation dated July 31, 2023.

SNC will retain the Function numbering in TS Table 3.3.6.1-1 by replacing the Function description with the word (Deleted). The same variation is made in the TS Bases. These differences are administrative and do not affect the applicability of TSTF-584 to the HNP Units 1 and 2 TS.

3.0 REGULATORY ANALYSIS

3.1 No Significant Hazards Consideration Analysis Southern Nuclear Operating Company (SNC) requests adoption of TSTF 584, "Eliminate Automatic RWCU System Isolation on SLC Initiation," into the Edwin I. Hatch Nuclear Plant (HNP) Units 1 and 2 Technical Specification (TS). TS 3.3.6.1, "Primary Containment Isolation Instrumentation," is revised to remove the requirement that the Reactor Water Cleanup (RWCU) System automatically isolate on manual initiation of the Standby Liquid Control (SLC) System. The SLC System is manually actuated in response to an Anticipated Transient Without Scram (ATWS) event. This change to the

Enclosure to NL-23-0928 Description and Assessment E-2 TS facilitates a future change to the plant design and procedures to require manually isolating the RWCU System when manually initiating the SLC System.

SNC has evaluated if a significant hazards consideration is involved with the proposed amendment(s) by focusing on the three standards set forth in 10 CFR 50.92, "Issuance of amendment," as discussed below:

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

Response: No The proposed change eliminates the TS requirement that the RWCU System automatically isolate on manual initiation of the SLC System. The SLC System is manually initiated in response to an ATWS event. The TS function that requires isolation of the RWCU System on SLC initiation is not an initiator to an ATWS event.

Should an ATWS event occur and the SLC System be manually initiated per plant procedure, plant procedures may also direct isolation of the RWCU System from the control room. In addition, an ATWS event will result in a lowering of reactor pressure vessel water level to the point that the RWCU System is automatically isolated (a function that will continue to be required by the TS.) As a result, removal of the RWCU System isolation on SLC initiation function from the TS will not result in an increase in the consequences of an ATWS event.

In addition to being used to mitigate an ATWS, the accident analysis credits manual actuation of the SLC system following a loss of coolant accident (LOCA) to control primary containment acidity. A LOCA will result in automatic isolation of the RWCU System by other TS-required functions. As a result, the proposed change will have no effect on the consequences of a LOCA.

Therefore, the proposed 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 eliminates the TS requirement that the RWCU System automatically isolate on manual initiation of the SLC System. The proposed change does not affect the design function of the RWCU System or the SLC System. The replacement of the automatic action to isolate the RWCU System on SLC initiation with manual action has the potential to introduce human error as a failure mechanism; however, in an ATWS event or LOCA, the RWCU System isolation would also be automatically initiated by low water level in the reactor pressure vessel. Consequently, no new failure mechanism is created, and no new or different kind of accident is created.

Enclosure to NL-23-0928 Description and Assessment E-3 Therefore, the proposed change does not create the possibility of a new or different kind of accident from any accident previously evaluated.

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

Response: No The proposed change eliminates the TS requirement that the RWCU System automatically isolate on manual initiation of the SLC System. The proposed change does not alter any controlling values of parameters established in the plant's licensing basis. The proposed change does not alter a design basis or safety limit (i.e., the controlling numerical value for a parameter established in the UFSAR or the license). Consequently, the margin of safety is not significantly affected.

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

Based on the above, SNC concludes that the proposed change presents no significant hazards consideration under the standards set forth in 10 CFR 50.92(c), and, accordingly, a finding of "no significant hazards consideration" is justified.

3.2 Conclusion In conclusion, based on the considerations discussed above, (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commissions regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

4.0 ENVIRONMENTAL CONSIDERATION

A review has determined that the proposed amendment would change a requirement with respect to installation or use of a facility component located within the restricted area, as defined in 10 CFR 20, or would change an inspection or surveillance requirement. However, the proposed amendment does not involve (i) a significant hazards consideration, (ii) a significant change in the types or a significant increase in the amounts of any effluents that may be released offsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure.

Accordingly, the proposed amendment meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(9). Therefore, pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the proposed amendment.

to Enclosure Technical Specification Pages (Markup)

Edwin I. Hatch Nuclear Plant - Units 1 & 2 Application to Revise Technical Specifications to Adopt TSTF-584, "Eliminate Automatic RWCU System Isolation on SLC Initiation" Proposed Technical Specification Changes (Markup)

Primary Containment Isolation Instrumentation 3.3.6.1 HATCH UNIT 1 3.3-53 Amendment No. 319 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME E.

As required by Required Action C.1 and referenced in Table 3.3.6.1-1.

E.1 Be in MODE 2.

6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> F.

As required by Required Action C.1 and referenced in Table 3.3.6.1-1.

F.1 Isolate the affected penetration flow path(s).

1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> G.

As required by Required Action C.1 and referenced in Table 3.3.6.1-1.

G.1 Isolate the affected penetration flow path(s).

24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> H.

As required by Required Action C.1 and referenced in Table 3.3.6.1-1.

OR Required Action and associated Completion Time of Condition F or G not met.

H.1 Be in MODE 3.

AND H.2 Be in MODE 4.

12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> 36 hours I.

As required by Required Action C.1 and referenced in Table 3.3.6.1-1.

I.1 Declare Standby Liquid Control (SLC) System inoperable.

OR I.2 Isolate the Reactor Water Cleanup (RWCU) System.

1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> 1 hour IJ.

As required by Required Action C.1 and referenced in Table 3.3.6.1-1.

IJ.1 Initiate action to restore channel to OPERABLE status.

Immediately

Primary Containment Isolation Instrumentation 3.3.6.1 HATCH UNIT 1 3.3-58 Amendment No. 315 Table 3.3.6.1-1 (page 4 of 5)

Primary Containment Isolation Instrumentation FUNCTION APPLICABLE MODES OR OTHER SPECIFIED CONDITIONS REQUIRED CHANNELS PER TRIP SYSTEM CONDITIONS REFERENCED FROM REQUIRED ACTION C.1 SURVEILLANCE REQUIREMENTS ALLOWABLE VALUE 4.

RCIC System Isolation (continued) g.

RCIC Suppression Pool Area Differential Temperature - High 1,2,3 1

F SR 3.3.6.1.1 SR 3.3.6.1.2 SR 3.3.6.1.5 SR 3.3.6.1.6 42°F h.

Emergency Area Cooler Temperature - High 1,2,3 1

F SR 3.3.6.1.1 SR 3.3.6.1.2 SR 3.3.6.1.5 SR 3.3.6.1.6 169°F 5.

RWCU System Isolation a.

Area Temperature - High 1,2,3 1 per area F

SR 3.3.6.1.1 SR 3.3.6.1.2 SR 3.3.6.1.5 SR 3.3.6.1.6 150°F b.

Area Ventilation Differential Temperature -

High 1,2,3 1 per area F

SR 3.3.6.1.1 SR 3.3.6.1.2 SR 3.3.6.1.5 SR 3.3.6.1.6 67°F c.

(Deleted)SLC System Initiation 1,2 1(b)

I SR 3.3.6.1.6 NA d.

Reactor Vessel Water Level - Low Low, Level 2 1,2,3 2

F SR 3.3.6.1.1 SR 3.3.6.1.2 SR 3.3.6.1.5 SR 3.3.6.1.6

-47 inches 6.

RHR Shutdown Cooling System Isolation a.

Reactor Steam Dome Pressure - High 1,2,3 1

F SR 3.3.6.1.1 SR 3.3.6.1.2 SR 3.3.6.1.5 SR 3.3.6.1.6 145 psig b.

Reactor Vessel Water Level - Low, Level 3 3

2 IJ SR 3.3.6.1.1 SR 3.3.6.1.2 SR 3.3.6.1.5 SR 3.3.6.1.6 0 inches (continued)

(b)

SLC System Initiation only inputs into one of the two trip systems.

Primary Containment Isolation Instrumentation 3.3.6.1 HATCH UNIT 2 3.3-53 Amendment No. 264 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME E.

As required by Required Action C.1 and referenced in Table 3.3.6.1-1.

E.1 Be in MODE 2.

6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> F.

As required by Required Action C.1 and referenced in Table 3.3.6.1-1.

F.1 Isolate the affected penetration flow path(s).

1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> G.

As required by Required Action C.1 and referenced in Table 3.3.6.1-1.

G.1 Isolate the affected penetration flow path(s).

24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> H.

As required by Required Action C.1 and referenced in Table 3.3.6.1-1.

OR Required Action and associated Completion Time of Condition F or G not met.

H.1 Be in MODE 3.

AND H.2 Be in MODE 4.

12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> 36 hours I.

As required by Required Action C.1 and referenced in Table 3.3.6.1-1.

I.1 Declare Standby Liquid Control (SLC) System inoperable.

OR I.2 Isolate the Reactor Water Cleanup (RWCU) System.

1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> 1 hour IJ.

As required by Required Action C.1 and referenced in Table 3.3.6.1-1.

IJ.1 Initiate action to restore channel to OPERABLE status.

Immediately

Primary Containment Isolation Instrumentation 3.3.6.1 HATCH UNIT 2 3.3-58 Amendment No. 260 Table 3.3.6.1-1 (page 4 of 5)

Primary Containment Isolation Instrumentation FUNCTION APPLICABLE MODES OR OTHER SPECIFIED CONDITIONS REQUIRED CHANNELS PER TRIP SYSTEM CONDITIONS REFERENCED FROM REQUIRED ACTION C.1 SURVEILLANCE REQUIREMENTS ALLOWABLE VALUE 4.

RCIC System Isolation (continued) g.

RCIC Suppression Pool Area Differential Temperature - High 1,2,3 1

F SR 3.3.6.1.1 SR 3.3.6.1.2 SR 3.3.6.1.5 SR 3.3.6.1.6 42°F h.

Emergency Area Cooler Temperature - High 1,2,3 1

F SR 3.3.6.1.1 SR 3.3.6.1.2 SR 3.3.6.1.5 SR 3.3.6.1.6 169°F 5.

RWCU System Isolation a.

Area Temperature - High 1,2,3 1 per area F

SR 3.3.6.1.1 SR 3.3.6.1.2 SR 3.3.6.1.5 SR 3.3.6.1.6 150°F b.

Area Ventilation Differential Temperature -

High 1,2,3 1 per area F

SR 3.3.6.1.1 SR 3.3.6.1.2 SR 3.3.6.1.5 SR 3.3.6.1.6 67°F c.

(Deleted)SLC System Initiation 1,2 1(b)

I SR 3.3.6.1.6 NA d.

Reactor Vessel Water Level - Low Low, Level 2 1,2,3 2

F SR 3.3.6.1.1 SR 3.3.6.1.2 SR 3.3.6.1.5 SR 3.3.6.1.6

- 47 inches 6.

RHR Shutdown Cooling System Isolation a.

Reactor Steam Dome Pressure - High 1,2,3 1

F SR 3.3.6.1.1 SR 3.3.6.1.2 SR 3.3.6.1.5 SR 3.3.6.1.6 145 psig b.

Reactor Vessel Water Level - Low, Level 3 3

2 IJ SR 3.3.6.1.1 SR 3.3.6.1.2 SR 3.3.6.1.5 SR 3.3.6.1.6 0 inches (continued)

(b)

SLC System Initiation only inputs into one of the two trip systems.

to Enclosure Revised Technical Specification Pages Edwin I. Hatch Nuclear Plant - Units 1 & 2 Application to Revise Technical Specifications to Adopt TSTF-584, "Eliminate Automatic RWCU System Isolation on SLC Initiation" Revised Technical Specification Pages

Primary Containment Isolation Instrumentation 3.3.6.1 HATCH UNIT 1 3.3-53 Amendment No.

ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME E.

As required by Required Action C.1 and referenced in Table 3.3.6.1-1.

E.1 Be in MODE 2.

6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> F.

As required by Required Action C.1 and referenced in Table 3.3.6.1-1.

F.1 Isolate the affected penetration flow path(s).

1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> G.

As required by Required Action C.1 and referenced in Table 3.3.6.1-1.

G.1 Isolate the affected penetration flow path(s).

24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> H.

As required by Required Action C.1 and referenced in Table 3.3.6.1-1.

OR Required Action and associated Completion Time of Condition F or G not met.

H.1 Be in MODE 3.

AND H.2 Be in MODE 4.

12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> 36 hours I.

As required by Required Action C.1 and referenced in Table 3.3.6.1-1.

I.1 Initiate action to restore channel to OPERABLE status.

Immediately

Primary Containment Isolation Instrumentation 3.3.6.1 HATCH UNIT 1 3.3-58 Amendment No.

Table 3.3.6.1-1 (page 4 of 5)

Primary Containment Isolation Instrumentation FUNCTION APPLICABLE MODES OR OTHER SPECIFIED CONDITIONS REQUIRED CHANNELS PER TRIP SYSTEM CONDITIONS REFERENCED FROM REQUIRED ACTION C.1 SURVEILLANCE REQUIREMENTS ALLOWABLE VALUE

4.

RCIC System Isolation (continued)

g.

RCIC Suppression Pool Area Differential Temperature - High 1,2,3 1

F SR 3.3.6.1.1 SR 3.3.6.1.2 SR 3.3.6.1.5 SR 3.3.6.1.6 42°F

h.

Emergency Area Cooler Temperature - High 1,2,3 1

F SR 3.3.6.1.1 SR 3.3.6.1.2 SR 3.3.6.1.5 SR 3.3.6.1.6 169°F

5.

RWCU System Isolation

a.

Area Temperature - High 1,2,3 1 per area F

SR 3.3.6.1.1 SR 3.3.6.1.2 SR 3.3.6.1.5 SR 3.3.6.1.6 150°F

b.

Area Ventilation Differential Temperature -

High 1,2,3 1 per area F

SR 3.3.6.1.1 SR 3.3.6.1.2 SR 3.3.6.1.5 SR 3.3.6.1.6 67°F

c.

(Deleted)

d.

Reactor Vessel Water Level - Low Low, Level 2 1,2,3 2

F SR 3.3.6.1.1 SR 3.3.6.1.2 SR 3.3.6.1.5 SR 3.3.6.1.6

-47 inches

6.

RHR Shutdown Cooling System Isolation

a.

Reactor Steam Dome Pressure - High 1,2,3 1

F SR 3.3.6.1.1 SR 3.3.6.1.2 SR 3.3.6.1.5 SR 3.3.6.1.6 145 psig

b.

Reactor Vessel Water Level - Low, Level 3 3

2 I

SR 3.3.6.1.1 SR 3.3.6.1.2 SR 3.3.6.1.5 SR 3.3.6.1.6 0 inches (continued)

Primary Containment Isolation Instrumentation 3.3.6.1 HATCH UNIT 2 3.3-53 Amendment No.

ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME E.

As required by Required Action C.1 and referenced in Table 3.3.6.1-1.

E.1 Be in MODE 2.

6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> F.

As required by Required Action C.1 and referenced in Table 3.3.6.1-1.

F.1 Isolate the affected penetration flow path(s).

1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> G.

As required by Required Action C.1 and referenced in Table 3.3.6.1-1.

G.1 Isolate the affected penetration flow path(s).

24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> H.

As required by Required Action C.1 and referenced in Table 3.3.6.1-1.

OR Required Action and associated Completion Time of Condition F or G not met.

H.1 Be in MODE 3.

AND H.2 Be in MODE 4.

12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> 36 hours I.

As required by Required Action C.1 and referenced in Table 3.3.6.1-1.

I.1 Initiate action to restore channel to OPERABLE status.

Immediately

Primary Containment Isolation Instrumentation 3.3.6.1 HATCH UNIT 2 3.3-58 Amendment No.

Table 3.3.6.1-1 (page 4 of 5)

Primary Containment Isolation Instrumentation FUNCTION APPLICABLE MODES OR OTHER SPECIFIED CONDITIONS REQUIRED CHANNELS PER TRIP SYSTEM CONDITIONS REFERENCED FROM REQUIRED ACTION C.1 SURVEILLANCE REQUIREMENTS ALLOWABLE VALUE

4.

RCIC System Isolation (continued)

g.

RCIC Suppression Pool Area Differential Temperature - High 1,2,3 1

F SR 3.3.6.1.1 SR 3.3.6.1.2 SR 3.3.6.1.5 SR 3.3.6.1.6 42°F

h.

Emergency Area Cooler Temperature - High 1,2,3 1

F SR 3.3.6.1.1 SR 3.3.6.1.2 SR 3.3.6.1.5 SR 3.3.6.1.6 169°F

5.

RWCU System Isolation

a.

Area Temperature - High 1,2,3 1 per area F

SR 3.3.6.1.1 SR 3.3.6.1.2 SR 3.3.6.1.5 SR 3.3.6.1.6 150°F

b.

Area Ventilation Differential Temperature -

High 1,2,3 1 per area F

SR 3.3.6.1.1 SR 3.3.6.1.2 SR 3.3.6.1.5 SR 3.3.6.1.6 67°F

c.

(Deleted)

d.

Reactor Vessel Water Level - Low Low, Level 2 1,2,3 2

F SR 3.3.6.1.1 SR 3.3.6.1.2 SR 3.3.6.1.5 SR 3.3.6.1.6

- 47 inches

6.

RHR Shutdown Cooling System Isolation

a.

Reactor Steam Dome Pressure - High 1,2,3 1

F SR 3.3.6.1.1 SR 3.3.6.1.2 SR 3.3.6.1.5 SR 3.3.6.1.6 145 psig

b.

Reactor Vessel Water Level - Low, Level 3 3

2 I

SR 3.3.6.1.1 SR 3.3.6.1.2 SR 3.3.6.1.5 SR 3.3.6.1.6 0 inches (continued) to Enclosure Technical Specification Bases Pages (Mark-up)

Edwin I. Hatch Nuclear Plant - Units 1 & 2 Application to Revise Technical Specifications to Adopt TSTF-584, "Eliminate Automatic RWCU System Isolation on SLC Initiation" Proposed Technical Specification Bases Changes (Mark-up) - For Information Only

Primary Containment Isolation Instrumentation B 3.3.6.1 (continued)

HATCH UNIT 1 B 3.3-142 REVISION 115 B 3.3 INSTRUMENTATION B 3.3.6.1 Primary Containment Isolation Instrumentation BASES BACKGROUND The primary containment isolation instrumentation automatically initiates closure of appropriate primary containment isolation valves (PCIVs). The function of the PCIVs, in combination with other accident mitigation systems, is to limit fission product release during and following postulated Design Basis Accidents (DBAs). Primary containment isolation within the time limits specified for those isolation valves designed to close automatically ensures that the release of radioactive material to the environment will be consistent with the assumptions used in the analyses for a DBA.

The isolation instrumentation includes the sensors, relays, and switches that are necessary to cause initiation of primary containment and reactor coolant pressure boundary (RCPB) isolation. Most channels include electronic equipment (e.g., trip units) that compares measured input signals with pre-established setpoints. When the setpoint is exceeded, the channel output relay actuates, which then outputs a primary containment isolation signal to the isolation logic.

Functional diversity is provided by monitoring a wide range of independent parameters. The input parameters to the isolation logics are: (a) reactor vessel water level, (b) area ambient and differential temperatures, (c) main steam line (MSL) flow measurement, (d) Standby Liquid Control (SLC) System initiation, (de) condenser vacuum, (ef) main steam line pressure, (fg) high pressure coolant injection (HPCI) and reactor core isolation cooling (RCIC) steam line flow, (gh) drywell radiation and pressure, (hi) HPCI and RCIC steam line pressure, (ij) HPCI and RCIC turbine exhaust diaphragm pressure, and (jk) reactor steam dome pressure. Redundant sensor input signals from each parameter are provided for initiation of isolation. The only exception is SLC System initiation.

Primary containment isolation instrumentation has inputs to the trip logic of the isolation functions listed below.

1. Main Steam Line Isolation Most MSL Isolation Functions receive inputs from four channels. The outputs from these channels are combined in a one-out-of-two taken twice logic to initiate isolation of all main steam isolation valves (MSIVs). The outputs from the same channels are arranged into two two-out-of-two logic trip systems to isolate all MSL drain valves and

Primary Containment Isolation Instrumentation B 3.3.6.1 (continued)

HATCH UNIT 1 B 3.3-145 REVISION 115 BASES BACKGROUND

5. Reactor Water Cleanup System Isolation (continued)

The Reactor Vessel Water Level - Low Low, Level 2 Isolation Function receives input from four reactor vessel water level channels.

The outputs from the reactor vessel water level channels are connected into two two-out-of-two trip systems. The Area Temperature - High Function receives input from six temperature monitors, three to each trip system. The Area Ventilation Differential Temperature - High Function receives input from six differential temperature monitors, three in each trip system. These are configured so that any one input will trip the associated trip system.

Each of the two trip systems is connected to one of the two valves on the RWCU penetration. However, the SLC System Initiation Function only provides an input to one trip system, thus closes only one valve.

RWCU Functions isolate the Group 5 valves.

6. RHR Shutdown Cooling System Isolation The Reactor Vessel Water Level - Low, Level 3 Function receives input from four reactor vessel water level channels. The outputs from the reactor vessel water level channels are connected to two two-out-of-two trip systems.

The Reactor Vessel Pressure - High Function receives input from two channels, with each channel in one trip system using a one-out-of-one logic. Each of the two trip systems is connected to one of the two valves on the shutdown cooling penetration.

RHR Shutdown Cooling System Isolation Functions isolate the Group 6 valves. The outboard shutdown cooling isolation valve, 1E11-F009, while not a PCIV, isolates on the same signals which isolate Group 6 valves.

7. Traversing Incore Probe (TIP) System Isolation The Reactor Vessel Water Level - Low, Level 3 Isolation Function receives input from two reactor vessel water level channels. The outputs from the reactor vessel water level channels are connected into one two-out-of-two logic trip system. The Drywell Pressure - High Isolation function receives input from two drywell pressure channels.

The outputs from the drywell pressure channels are connected into one two-out-of-two logic trip system.

When either isolation Function actuates, the TIP drive mechanisms will withdraw the TIPs, if inserted, and close the inboard TIP system isolation ball valves when the TIPs are fully withdrawn. The outboard TIP system isolation valves are manual shear valves.

TIP System Isolation Functions isolate the Group 13 valves (inboard isolation ball valves).

Primary Containment Isolation Instrumentation B 3.3.6.1 (continued)

HATCH UNIT 1 B 3.3-158 REVISION 115 BASES APPLICABLE 3.g., 4.f. Suppression Pool Area Temperature - Time Delay Relay SAFETY ANALYSES, (continued)

LCO, and APPLICABILITY These Functions isolate the Group 3 (and 1E41-F041) and 4 valves, as appropriate.

5. Reactor Water Cleanup System Isolation 5.a., 5.b. Area and Area Ventilation Differential Temperature - High RWCU area and area ventilation differential temperatures are provided to detect a leak from the RWCU System. The isolation occurs even when very small leaks have occurred. If the small leak continues without isolation, offsite dose limits may be reached. Credit for these instruments is not taken in any transient or accident analysis in the FSAR, since bounding analyses are performed for large breaks such as recirculation or MSL breaks.

Area and area ventilation differential temperature signals are initiated from temperature elements that are located in the area that is being monitored. Six RTDs provide input to the Area Temperature - High Function (two per area). Six channels are required to be OPERABLE to ensure that no single instrument failure can preclude the isolation function.

Twelve RTDs provide input to the Area Ventilation Differential Temperature - High Function. The output of these RTDs is used to determine the differential temperature. Each channel consists of a differential temperature instrument that receives inputs from RTDs that are located in the inlet and outlet of the area cooling system and for a total of six available channels (two per area). Six channels are required to be OPERABLE to ensure that no single instrument failure can preclude the isolation function.

The Area and Area Ventilation Differential Temperature - High Allowable Values are set low enough to detect a leak equivalent to 25 gpm.

These Functions isolate the Group 5 valves.

5.c. (Deleted)SLC System Initiation The isolation of the RWCU System is required when the SLC System has been initiated to prevent dilution and removal of the boron

Primary Containment Isolation Instrumentation B 3.3.6.1 (continued)

HATCH UNIT 1 B 3.3-159 REVISION 115 BASES APPLICABLE 5.c. SLC System Initiation (continued)

SAFETY ANALYSES, LCO, and solution by the RWCU System (Ref. 3). SLC System initiation signal APPLICABILITY is initiated from the SLC pump start signal.

There is no Allowable Value associated with this Function since the channel is mechanically actuated based solely on the position of the SLC System initiation switch.

One channel of the SLC System Initiation Function is available and is required to be OPERABLE only in MODES 1 and 2, since these are the only MODES where the reactor can be critical, and these MODES are consistent with the Applicability for the SLC System (LCO 3.1.7).

As noted [footnote (c) to Table 3.3.6.1-1], this Function is only required to close one of the Group 5 RWCU isolation valves since the signal only provides input into one of the two trip systems.

5.d. Reactor Vessel Water Level - Low Low, Level 2 Low RPV water level indicates that the capability to cool the fuel may be threatened. Should RPV water level decrease too far, fuel damage could result. Therefore, isolation of some interfaces with the reactor vessel occurs to isolate the potential sources of a break. The isolation of the RWCU System on Level 2 supports actions to ensure that the fuel peak cladding temperature remains below the limits of 10 CFR 50.46. The Reactor Vessel Water Level - Low Low, Level 2 Function associated with RWCU isolation is not directly assumed in the FSAR safety analyses because the RWCU System line break is bounded by breaks of larger systems (recirculation and MSL breaks are more limiting).

Reactor Vessel Water Level - Low Low, Level 2 signals are initiated from four level transmitters that sense the difference between the pressure due to a constant column of water (reference leg) and the pressure due to the actual water level (variable leg) in the vessel.

Four channels of Reactor Vessel Water Level - Low Low, Level 2 Function are available and are required to be OPERABLE to ensure that no single instrument failure can preclude the isolation function.

Primary Containment Isolation Instrumentation B 3.3.6.1 (continued)

HATCH UNIT 1 B 3.3-167 REVISION 115 BASES ACTIONS G.1 and G.2 (continued)

If the channel is not restored to OPERABLE status or placed in trip within the allowed Completion Time, plant operations may continue if the affected penetration flow path(s) is isolated. Isolating the affected penetration flow path(s) accomplishes the safety function of the inoperable channels. The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> Completion Time is acceptable due to the fact that the TIP System penetration is a small bore (approximately 1/2 inch), its isolation in a design basis event (with loss of offsite power) would be via the manually operated shear valves, and the ability to manually isolate by either the normal isolation valve or the shear valve is unaffected by the inoperable instrumentation.

Alternately, if it is not desired to isolate the affected penetration flow path(s), Condition H must be entered and its Required Actions taken.

H.1 and H.2 If the channel is not restored to OPERABLE status or placed in trip within the allowed Completion Time, or any Required Action of Condition F or G is not met and the associated Completion Time has expired, the plant must be placed in a MODE or other specified condition in which the LCO does not apply. This is done by placing the plant in at least MODE 3 within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in MODE 4 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. The allowed Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems.

I.1 and I.2 If the channel is not restored to OPERABLE status or placed in trip within the allowed Completion Time, the SLC System is declared inoperable or the RWCU System is isolated. Since this Function is required to ensure that the SLC System performs its intended function, sufficient remedial measures are provided by declaring the SLC System inoperable or isolating the RWCU System.

The 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Completion Time is acceptable because it minimizes risk while allowing sufficient time for personnel to isolate the RWCU System.

Primary Containment Isolation Instrumentation B 3.3.6.1 (continued)

HATCH UNIT 1 B 3.3-168 REVISION 115 BASES ACTIONS IJ.1 (continued)

If the channel is not restored to OPERABLE status or placed in trip within the allowed Completion Time, the associated penetration flow path should be closed. Actions must continue until the channel is restored to OPERABLE status.

SURVEILLANCE As noted at the beginning of the SRs, the SRs for each Primary REQUIREMENTS Containment Isolation instrumentation Function are found in the SRs column of Table 3.3.6.1-1.

The Surveillances are modified by a Note to indicate that when a channel is placed in an inoperable status solely for performance of required Surveillances, entry into associated Conditions and Required Actions may be delayed for up to 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> provided the associated Function maintains isolation capability. Upon completion of the Surveillance, or expiration of the 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> allowance, the channel must be returned to OPERABLE status or the applicable Condition entered and Required Actions taken. This Note is based on the reliability analysis (Refs. 4 and 5) assumption of the average time required to perform channel surveillance. That analysis demonstrated that the 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> testing allowance does not significantly reduce the probability that the PCIVs will isolate the penetration flow path(s) when necessary.

Primary Containment Isolation Instrumentation B 3.3.6.1 (continued)

HATCH UNIT 2 B 3.3-142 REVISION 127 B 3.3 INSTRUMENTATION B 3.3.6.1 Primary Containment Isolation Instrumentation BASES BACKGROUND The primary containment isolation instrumentation automatically initiates closure of appropriate primary containment isolation valves (PCIVs). The function of the PCIVs, in combination with other accident mitigation systems, is to limit fission product release during and following postulated Design Basis Accidents (DBAs). Primary containment isolation within the time limits specified for those isolation valves designed to close automatically ensures that the release of radioactive material to the environment will be consistent with the assumptions used in the analyses for a DBA.

The isolation instrumentation includes the sensors, relays, and switches that are necessary to cause initiation of primary containment and reactor coolant pressure boundary (RCPB) isolation. Most channels include electronic equipment (e.g., trip units) that compares measured input signals with pre-established setpoints. When the setpoint is exceeded, the channel output relay actuates, which then outputs a primary containment isolation signal to the isolation logic.

Functional diversity is provided by monitoring a wide range of independent parameters. The input parameters to the isolation logics are (a) reactor vessel water level, (b) area ambient and differential temperatures, (c) main steam line (MSL) flow measurement, (d) Standby Liquid Control (SLC) System initiation, (de) condenser vacuum, (ef) main steam line pressure, (fg) high pressure coolant injection (HPCI) and reactor core isolation cooling (RCIC) steam line flow, (gh) drywell radiation and pressure, (hi) HPCI and RCIC steam line pressure, (ij) HPCI and RCIC turbine exhaust diaphragm pressure, and (jk) reactor steam dome pressure. Redundant sensor input signals from each parameter are provided for initiation of isolation. The only exception is SLC System initiation.

Primary containment isolation instrumentation has inputs to the trip logic of the isolation functions listed below.

1. Main Steam Line Isolation Most MSL Isolation Functions receive inputs from four channels. The outputs from these channels are combined in a one-out-of-two taken twice logic to initiate isolation of all main steam isolation valves (MSIVs). The outputs from the same channels are arranged into two two-out-of-two logic trip systems to isolate all MSL drain valves and

Primary Containment Isolation Instrumentation B 3.3.6.1 (continued)

HATCH UNIT 2 B 3.3-145 REVISION 127 BASES BACKGROUND

5. Reactor Water Cleanup System Isolation (continued)

The Reactor Vessel Water Level - Low Low, Level 2 Isolation Function receives input from four reactor vessel water level channels.

The outputs from the reactor vessel water level channels are connected into two two-out-of-two trip systems. The Area Temperature - High Function receives input from six temperature monitors, three to each trip system. The Area Ventilation Differential Temperature - High Function receives input from six differential temperature monitors, three in each trip system. These are configured so that any one input will trip the associated trip system.

Each of the two trip systems is connected to one of the two valves on the RWCU penetration. However, the SLC System Initiation Function only provides an input to one trip system, thus closes only one valve.

RWCU Functions isolate the Group 5 valves.

6. RHR Shutdown Cooling System Isolation The Reactor Vessel Water Level - Low, Level 3 Function receives input from four reactor vessel water level channels. The outputs from the reactor vessel water level channels are connected to two-out-of-two trip systems.

The Reactor Vessel Pressure - High Function receives input from two channels, with each channel in one trip system using a one-out-of-one logic. Each of the two trip systems is connected to one of the two valves on the shutdown cooling penetration.

RHR Shutdown Cooling System Isolation Functions isolate the Group 6 valves. The outboard shutdown cooling isolation valve, 2E11-F009, while not a PCIV, isolates on the same signals which isolate Group 6 valves.

7. Traversing Incore Probe (TIP) System Isolation The Reactor Vessel Water Level - Low, Level 3 Isolation Function receives input from two reactor vessel water level channels. The outputs from the reactor vessel water level channels are connected into one two-out-of-two logic trip system. The Drywell Pressure - High Isolation function receives input from two drywell pressure channels.

The outputs from the drywell pressure channels are connected into one two-out-of-two logic trip system.

When either isolation Function actuates, the TIP drive mechanisms will withdraw the TIPs, if inserted, and close the inboard TIP system isolation ball valves when the TIPs are fully withdrawn. The outboard TIP system isolation valves are manual shear valves.

TIP System Isolation Functions isolate the Group 13 valves (inboard isolation ball valves).

Primary Containment Isolation Instrumentation B 3.3.6.1 (continued)

HATCH UNIT 2 B 3.3-157 REVISION 127 BASES APPLICABLE 3.g., 4.f. Suppression Pool Area Temperature - Time Delay Relay SAFETY ANALYSES, (continued)

LCO, and APPLICABILITY These Functions isolate the Group 3 (and 1E41-F041) and 4 valves, as appropriate.

5. Reactor Water Cleanup System Isolation 5.a., 5.b. Area and Area Ventilation Differential Temperature - High RWCU area and area ventilation differential temperatures are provided to detect a leak from the RWCU System. The isolation occurs even when very small leaks have occurred. If the small leak continues without isolation, offsite dose limits may be reached. Credit for these instruments is not taken in any transient or accident analysis in the FSAR, since bounding analyses are performed for large breaks such as recirculation or MSL breaks.

Area and area ventilation differential temperature signals are initiated from temperature elements that are located in the area that is being monitored. Six RTDs provide input to the Area Temperature - High Function (two per area). Six channels are required to be OPERABLE to ensure that no single instrument failure can preclude the isolation function.

Twelve RTDs provide input to the Area Ventilation Differential Temperature - High Function. The output of these RTDs is used to determine the differential temperature. Each channel consists of a differential temperature instrument that receives inputs from RTDs that are located in the inlet and outlet of the area cooling system and for a total of six available channels (two per area). Six channels are required to be OPERABLE to ensure that no single instrument failure can preclude the isolation function.

The Area and Area Ventilation Differential Temperature - High Allowable Values are set low enough to detect a leak equivalent to 25 gpm.

These Functions isolate the Group 5 valves.

5.c. (Deleted)SLC System Initiation The isolation of the RWCU System is required when the SLC System has been initiated to prevent dilution and removal of the boron

Primary Containment Isolation Instrumentation B 3.3.6.1 (continued)

HATCH UNIT 2 B 3.3-158 REVISION 127 BASES APPLICABLE 5.c. SLC System Initiation (continued)

SAFETY ANALYSES, LCO, and solution by the RWCU System (Ref. 3). SLC System initiation signal APPLICABILITY is initiated from the SLC pump start signal.

There is no Allowable Value associated with this Function since the channel is mechanically actuated based solely on the position of the SLC System initiation switch.

One channel of the SLC System Initiation Function is available and is required to be OPERABLE only in MODES 1 and 2, since these are the only MODES where the reactor can be critical, and these MODES are consistent with the Applicability for the SLC System (LCO 3.1.7).

As noted (footnote (c) to Table 3.3.6.1-1), this Function is only required to close one of the Group 5 RWCU isolation valves since the signal only provides input into one of the two trip systems.

5.d. Reactor Vessel Water Level - Low Low, Level 2 Low RPV water level indicates that the capability to cool the fuel may be threatened. Should RPV water level decrease too far, fuel damage could result. Therefore, isolation of some interfaces with the reactor vessel occurs to isolate the potential sources of a break. The isolation of the RWCU System on Level 2 supports actions to ensure that the fuel peak cladding temperature remains below the limits of 10 CFR 50.46. The Reactor Vessel Water Level - Low Low, Level 2 Function associated with RWCU isolation is not directly assumed in the FSAR safety analyses because the RWCU System line break is bounded by breaks of larger systems (recirculation and MSL breaks are more limiting).

Reactor Vessel Water Level - Low Low, Level 2 signals are initiated from four level transmitters that sense the difference between the pressure due to a constant column of water (reference leg) and the pressure due to the actual water level (variable leg) in the vessel.

Four channels of Reactor Vessel Water Level - Low Low, Level 2 Function are available and are required to be OPERABLE to ensure that no single instrument failure can preclude the isolation function.

Primary Containment Isolation Instrumentation B 3.3.6.1 (continued)

HATCH UNIT 2 B 3.3-166 REVISION 127 BASES ACTIONS F.1 (continued)

Alternately, if it is not desired to isolate the affected penetration flow path(s) (e.g., as in the case where isolating the penetration flow path(s) could result in a reactor scram), Condition H must be entered and its Required Actions taken.

The 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Completion Time is acceptable because it minimizes risk while allowing sufficient time for personnel to isolate the affected penetration flow path(s).

G.1 and G.2 If the channel is not restored to OPERABLE status or placed in trip within the allowed Completion Time, plant operations may continue if the affected penetration flow path(s) is isolated. Isolating the affected penetration flow path(s) accomplishes the safety function of the inoperable channels. The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> Completion Time is acceptable due to the fact that the TIP System penetration is a small bore (approximately 1/2 inch), its isolation in a design basis event (with loss of offsite power) would be via the manually operated shear valves, and the ability to manually isolate by either that normal isolation valve or the shear valve is unaffected by the inoperable instrumentation.

Alternately, if it is not desired to isolate the affected penetration flow path(s), Condition H must be entered and its Required Actions taken.

H.1 and H.2 If the channel is not restored to OPERABLE status or placed in trip within the allowed Completion Time, or any Required Action of Condition F or G is not met and the associated Completion Time has expired, the plant must be placed in a MODE or other specified condition in which the LCO does not apply. This is done by placing the plant in at least MODE 3 within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in MODE 4 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. The allowed Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems.

I.1 and I.2 If the channel is not restored to OPERABLE status or placed in trip within the allowed Completion Time, the SLC System is declared inoperable or the RWCU System is isolated. Since this Function is required to ensure that the SLC System performs its intended function, sufficient remedial measures are provided by declaring the SLC System inoperable or isolating the RWCU System.

Primary Containment Isolation Instrumentation B 3.3.6.1 (continued)

HATCH UNIT 2 B 3.3-167 REVISION 127 BASES ACTIONS I.1 and I.2 (continued)

The 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Completion Time is acceptable because it minimizes risk while allowing sufficient time for personnel to isolate the RWCU System.

IJ.1 If the channel is not restored to OPERABLE status or placed in trip within the allowed Completion Time, the associated penetration flow path should be closed. Actions must continue until the channel is restored to OPERABLE status.

SURVEILLANCE As noted at the beginning of the SRs, the SRs for each Primary REQUIREMENTS Containment Isolation instrumentation Function are found in the SRs column of Table 3.3.6.1-1.

The Surveillances are modified by a Note to indicate that when a channel is placed in an inoperable status solely for performance of required Surveillances, entry into associated Conditions and Required Actions may be delayed for up to 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> provided the associated Function maintains isolation capability. Upon completion of the Surveillance, or expiration of the 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> allowance, the channel must be returned to OPERABLE status or the applicable Condition entered and Required Actions taken. This Note is based on the reliability analysis (Refs. 4 and 5) assumption of the average time required to perform channel surveillance. That analysis demonstrated that the 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> testing allowance does not significantly reduce the probability that the PCIVs will isolate the penetration flow path(s) when necessary.

SR 3.3.6.1.1 Performance of the CHANNEL CHECK ensures that a gross failure of instrumentation has not occurred. A CHANNEL CHECK is normally a comparison of the parameter indicated on one channel to a similar parameter on other channels. It is based on the assumption that