BVY 12-078, Technical Specifications Proposed Change 297, Supplement 2 Response to Request for Additional Information: Difference between revisions
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{{#Wiki_filter: | {{#Wiki_filter:Entergy Nuclear Operations, Inc. | ||
Vermont Yankee 320 Governor Hunt Rd. | |||
Vernon, VT SPEntergy 802-257-7711 Christopher J. Wamser Site Vice President BVY 12-078 November 20, 2012 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 | |||
==SUBJECT:== | ==SUBJECT:== | ||
Technical Specifications Proposed Change 297, Supplement 2 Response to Request for Additional Information Vermont Yankee Nuclear Power Station Docket No. 50-271 License No. DPR-28 | |||
==REFERENCES:== | ==REFERENCES:== | ||
: 1. Letter, Entergy Nuclear Operations, Inc. to USNRC, "Technical Specification Proposed Change No. 297 Suppression Chamber-Drywell Leak Rate Test Surveillance Frequency Change," BVY 12-005, dated February 1, 2012 | |||
: 2. Letter, Entergy Nuclear Operations, Inc. to USNRC, "Technical Specification Proposed Change No. 297, Supplement 1, Response to Request for Additional Information," BVY 12-055, dated August 7, 2012 | |||
==Dear Sir or Madam:== | |||
In Reference 1, Entergy Nuclear Operations, Inc. (Entergy) submitted a request, as supplemented by Reference 2, for an amendment to the renewed facility operating license Technical Specifications (TS) for Vermont Yankee requesting a change to the TS related to the drywell to suppression chamber vacuum breakers. This letter provides supplemental information to address a request for additional information (RAI) received on November 1, 2012 and discussed on a teleconference held November 1, 2012. | |||
Attachment 1 to this submittal provides Entergy's response to the RAI and Attachment 2 provides revised TS and TS Bases pages reflecting the changes proposed to address NRC questions. The TS Bases page is provided for information only. | |||
This supplement to the original license amendment request does not change the scope or conclusions in the original application, nor does it change Entergy's determination of no significant hazards consideration. | |||
There are no new regulatory commitments being made in this letter. | |||
MV] | |||
BVY 12-078 / Page 2 of 2 Should you have any questions concerning this letter or require additional information, please contact Robert Wanczyk at 802-451-3166. | BVY 12-078 / Page 2 of 2 Should you have any questions concerning this letter or require additional information, please contact Robert Wanczyk at 802-451-3166. | ||
I declare under penalty of perjury that the foregoing is true and correct. Executed on November 20, 2012.Sincerely, CJW/plc Attachments: | I declare under penalty of perjury that the foregoing is true and correct. Executed on November 20, 2012. | ||
Sincerely, CJW/plc Attachments: 1. Response to Request for Additional Information | |||
: 2. Retyped Technical Specification and Bases Pages cc: William M. Dean Regional Administrator, Region 1 U.S. Nuclear Regulatory Commission 2100 Renaissance Blvd, Suite 100 King of Prussia, PA 19406-2713 Mr. Richard V. Guzman, Project Manager Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop O-8-C2 Washington, DC 20555 USNRC Resident Inspector Entergy Nuclear Vermont Yankee, LLC 320 Governor Hunt Road Vernon, Vermont 05354 Ms. Elizabeth Miller Commissioner Vermont Department of Public Service 112 State Street -Drawer 20 Montpelier, Vermont 05620-2601 BVY 12-078 Docket 50-271 Attachment 1 Proposed Change 297, Supplement 2 Response to Request for Additional Information | : 2. Retyped Technical Specification and Bases Pages cc: William M. Dean Regional Administrator, Region 1 U.S. Nuclear Regulatory Commission 2100 Renaissance Blvd, Suite 100 King of Prussia, PA 19406-2713 Mr. Richard V. Guzman, Project Manager Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop O-8-C2 Washington, DC 20555 USNRC Resident Inspector Entergy Nuclear Vermont Yankee, LLC 320 Governor Hunt Road Vernon, Vermont 05354 Ms. Elizabeth Miller Commissioner Vermont Department of Public Service 112 State Street - Drawer 20 Montpelier, Vermont 05620-2601 | ||
.1 BVY 12-078 / Attachment 1 / page 1 of 1 Response to Request for Additional Information (RAI)RAI The proposed Technical Specification (TS) change would allow the drywell-to-suppression chamber leak rate surveillance test to be performed any time during an operating cycle (OC) of 18 months as opposed to performing the test during every refueling outage (RFO). The proposed change would therefore allow the test frequency to be revised from a current frequency of 18 months to anywhere up to 36 months. In case the test is not performed during an RFO, and the plant is brought to power, it could allow entering a MODE where containment integrity is required without having met the surveillance requirement (SR). This would be in conflict with SR 4.0.1 which states: SRs shall be met during the modes or other specified conditions in the Applicability for individual LCOs, unless otherwise stated in the SR. | |||
Response Entergy agrees with this observation and proposes to revise the specified frequency of the drywell-to-suppression chamber leak rate test to once every 18 months, consistent with SR 3.6.1.1.2 in NUREG-1433 "Standard Technical Specifications General Electric Plants, BWR/4." Attachment 2 provides revised TS and TS Bases pages reflecting this change. | BVY 12-078 Docket 50-271 Attachment 1 Proposed Change 297, Supplement 2 Response to Request for Additional Information | ||
BVY 12-078 Docket 50-271 Attachment 2 Proposed Change 297, Supplement 2 Retyped Technical Specification and Bases Pages VYNPS 3.7 LIMITING CONDITIONS FOR | |||
: | .1 BVY 12-078 / Attachment 1 / page 1 of 1 Response to Request for Additional Information (RAI) | ||
RAI The proposed Technical Specification (TS) change would allow the drywell-to-suppression chamber leak rate surveillance test to be performed any time during an operating cycle (OC) of 18 months as opposed to performing the test during every refueling outage (RFO). The proposed change would therefore allow the test frequency to be revised from a current frequency of 18 months to anywhere up to 36 months. In case the test is not performed during an RFO, and the plant is brought to power, it could allow entering a MODE where containment integrity is required without having met the surveillance requirement (SR). This would be in conflict with SR 4.0.1 which states: | |||
SRs shall be met during the modes or other specified conditions in the Applicability for individual LCOs, unless otherwise stated in the SR. Failureto meet a Surveillance, whether such failure is experienced during the performance of the Surveillance or between performances of the Surveillance, shall be failure to meet the LCO. Failureto perform a Surveillance within the specified frequency shall be failure to meet the LCO except as provided in SR 4.0.3. Surveillances do not have to be performed on inoperableequipment or variablesoutside specified limits. | |||
Please explain how the proposed TS change ensures that the SR is met consistently every 18 months. | |||
Note that in Standard Technical Specification (STS) (NUREG-1433, Volume 1, Revision 3), | |||
the frequency for SR 3.6.1.1.2 is 18 months and has to be met in Modes 1, 2, and 3. The test frequency prevents from entering from MODE 5 to Mode 1, 2, or 3 without verifying containment integrity. | |||
===Response=== | |||
Entergy agrees with this observation and proposes to revise the specified frequency of the drywell-to-suppression chamber leak rate test to once every 18 months, consistent with SR 3.6.1.1.2 in NUREG-1433 "Standard Technical Specifications General Electric Plants, BWR/4." | |||
Attachment 2 provides revised TS and TS Bases pages reflecting this change. | |||
BVY 12-078 Docket 50-271 Attachment 2 Proposed Change 297, Supplement 2 Retyped Technical Specification and Bases Pages | |||
VYNPS 3.7 LIMITING CONDITIONS FOR 4.7 SURVEILLANCE REQUIREMENTS OPERATION at normal cooldown rates if the torus water temperature exceeds 120*F. | |||
: e. Minimum Water Volume | |||
- 68,000 cubic feet | |||
: f. Maximum Water Volume | |||
- 70,000 cubic feet | |||
: 2. Primary containment 2. Primary Containment integrity shall be Surveillances maintained at all times when the reactor is a. The primary containment critical or when the integrity shall be reactor water temperature demonstrated as required is above 212°F and fuel is by the Primary in the reactor vessel Containment Leakage Rate except while performing Testing Program (PCLRTP). | |||
low power physics tests at atmospheric pressure at b. Once every 18 months, a power levels not to exceed drywell to suppression chamber leak rate test 5 Mw(t). | |||
shall demonstrate that with an initial | |||
: 3. If a portion of a system that is considered to be differential pressure of not less than 1.0 psi, an extension of primary containment is to be the differential pressure opened, isolate the decay rate shall not affected penetration flow exceed the equivalent of path by use of at least the leakage rate through one closed and deactivated a 1-inch orifice. Should there be two consecutive automatic valve, closed manual valve or blind test failures the test flange. frequency shall be changed to once every 9 months until two | |||
: 4. Whenever primary containment integrity is consecutive tests pass. | |||
required: | |||
: 3. (Blank) | |||
: a. The leakage rate from | |||
: 4. In accordance with the any one main steam isolation valve (MSIV) PCLRTP, verify that the shall not exceed 62 following leakage rates are within acceptable limits: | |||
scfh at 44 psig (Pa); | |||
: b. The combined leakage a. The leakage rate through rate from the main each MSIV; steam pathways shall not exceed 124 scfh at b. The combined leakage rate for the main steam 44 psig (Pa); and pathways; and | |||
: c. The combined leakage rate from the secondary c. The combined leakage rate for the secondary containment bypass pathways shall not containment bypass exceed 5 scfh at 44 pathways. | |||
psig (Pa). | |||
Amendment No. &G, 4-5-2-, 4-6-, 4-74, 2-2-3 147 | |||
VYNPS I | |||
3.7 LIMITING CONDITIONS FOR 4.7 SURVEILLANCE REQUIREMENTS OPERATION line is verified to be closed and conditions required by 3.7.D.2 are met. | |||
: 6. Pressure Suppression 6. Pressure Suppression Chamber - Drywell Vacuum Chamber - Drywell Vacuum Breakers Breakers | |||
: a. When primary a. Periodic Operability containment is Tests required, all suppression chamber Operability testing | |||
- drywell vacuum of the vacuum breakers shall be breakers shall be in operable except accordance with during testing and Specification 4.6.E as stated in and within 12 hours Specifications after any discharge 3.7.A.6.b and c, of steam to the below. Suppression suppression chamber chamber - drywell from the vacuum breakers safety/relief valves shall be considered and within 12 hours operable if: following an operation that (1) The valve is causes any of the demonstrated vacuum breakers to to open fully open. Operability with the of the corresponding applied force position switches at all valve and position positions not indicators and exceeding alarms shall be that verified monthly and equivalent to following any 0.5 psi maintenance. | |||
acting on the suppression b. Refueling Outage chamber face Test of the valve disk. (1) All suppression (2) The valve can chamber - | |||
be closed by drywell gravity, when vacuum released breaker after being position opened by indication remote or and alarm manual means, systems shall to within not be calibrated greater than and the functionally equivalent of tested. | |||
0.05 inch at all points (2) Deleted along the seal surface of the disk. | |||
Amendment No. 1-14, 2-31 149 | |||
VYNPS 3.7 LIMITING CONDITIONS FOR 4.7 SURVEILLANCE REQUIREMENTS OPERATION (3) The position alarm system will annunciate in the control room if the valve opening exceeds the equivalent of 0.05 inch at all points along the seal surface of the disk. (3) Deleted | |||
: b. Up to two (2) of the ten (10) suppression chamber - drywell vacuum breakers may be determined to be inoperable provided 7. Oxygen Concentration that they are secured, or known to The primary containment be, in the closed oxygen concentration shall position. be measured and recorded on a weekly basis. | |||
: c. Reactor operation may continue for fifteen (15) days provided that at least one position alarm circuit for each vacuum breaker is operable and each suppression chamber | |||
- drywell vacuum breaker is physically verified to be closed immediately and daily thereafter. | |||
: 7. Oxygen Concentration | : 7. Oxygen Concentration | ||
: a. The primary containment atmosphere shall be reduced to less than 4 percent oxygen by volume with nitrogen gas while in the RUN MODE during the time period: i.From 24 hours after thermal power is greater than 15% rated thermal power following startup, to Amendment No. 4-1-4, 4-2-8., 2--2f 2-3-, | : a. The primary containment atmosphere shall be reduced to less than 4 percent oxygen by volume with nitrogen gas while in the RUN MODE during the time period: | ||
The 2 psig set point will not be exceeded. | i.From 24 hours after thermal power is greater than 15% rated thermal power following startup, to Amendment No. 4-1-4, 4-2-8.,2--2f 2-3-, 150 | ||
The subsequent suppression chamber pressure transient (if any) will be monitored with a sensitive pressure gauge. If the drywell pressure cannot be increased by 1 psi over the suppression chamber pressure it would be because a significant leakage path exists; in this event the leakage source will be identified and eliminated before power operation is resumed. If the drywell pressure can be increased by 1 psi over the suppression chamber the rate of change of the suppression chamber pressure must not exceed a rate equivalent to the rate of leakage from the drywell through a 1-inch orifice. In the event the rate of change exceeds this value then the plant will be shut down, if operating, the source of leakage will be identified and addressed before power operation is resumed. Two consecutive test failures, however, would indicate unexpected primary containment degradation; in this event, increasing the frequency to once every 9 months is required until the situation is remedied as evidenced by passing two consecutive tests.The drywell-suppression chamber vacuum breakers are exercised in accordance with Specification 4.6.E, following termination of discharge of steam into the suppression chamber from the safety/relief valves and following any operation that causes the vacuum breakers to open. This monitoring of valve operability is intended to assure that valve operability and position indication system performance does not degrade between refueling inspections. | |||
When a vacuum breaker valve is exercised through an opening-closing cycle, the position indicating lights are designed to function as follows: Full Closed 2 White -On (Closed to <0.050" open)Open 2 White -Off (>0.050" open to full open)Experience has shown that a weekly measurement of the oxygen concentration in the primary containment assures adequate surveillance of the primary containment atmosphere. | VYNPS BASES: 4.7 (Cont'd) | ||
B. and C. Standby Gas Treatment System and Secondary Containment System Initiating reactor building isolation and operation of the standby gas treatment system to maintain at least a 0.15 inch of water vacuum within the secondary containment provides an adequate test of the operation of the reactor building isolation valves, leakage tightness of the reactor building, and performance of the standby gas treatment system. The testing of reactor building automatic ventilation system isolation valves in accordance with Technical Specification 4.6.E demonstrates the operability of these valves. In addition, functional testing of initiating sensors and associated trip channels demonstrates the capability for automatic actuation. | Every 18 months, a leak rate test shall be performed to verify that significant leakage flow paths do not exist between the drywell and suppression chamber. The drywell pressure will be increased by at least 1 psi with respect to the suppression chamber pressure and held constant. The 2 psig set point will not be exceeded. The subsequent suppression chamber pressure transient (if any) will be monitored with a sensitive pressure gauge. If the drywell pressure cannot be increased by 1 psi over the suppression chamber pressure it would be because a significant leakage path exists; in this event the leakage source will be identified and eliminated before power operation is resumed. If the drywell pressure can be increased by 1 psi over the suppression chamber the rate of change of the suppression chamber pressure must not exceed a rate equivalent to the rate of leakage from the drywell through a 1-inch orifice. In the event the rate of change exceeds this value then the plant will be shut down, if operating, the source of leakage will be identified and addressed before power operation is resumed. Two consecutive test failures, however, would indicate unexpected primary containment degradation; in this event, increasing the frequency to once every 9 months is required until the situation is remedied as evidenced by passing two consecutive tests. | ||
Periodic testing gives sufficient confidence of reactor building integrity and standby gas treatment system performance capability. | The drywell-suppression chamber vacuum breakers are exercised in accordance with Specification 4.6.E, following termination of discharge of steam into the suppression chamber from the safety/relief valves and following any operation that causes the vacuum breakers to open. This monitoring of valve operability is intended to assure that valve operability and position indication system performance does not degrade between refueling inspections. | ||
Amendment No. 4-24, 444, 2-341 169}} | When a vacuum breaker valve is exercised through an opening-closing cycle, the position indicating lights are designed to function as follows: | ||
Full Closed 2 White - On (Closed to <0.050" open) | |||
Open 2 White - Off | |||
(>0.050" open to full open) | |||
Experience has shown that a weekly measurement of the oxygen concentration in the primary containment assures adequate surveillance of the primary containment atmosphere. | |||
B. and C. Standby Gas Treatment System and Secondary Containment System Initiating reactor building isolation and operation of the standby gas treatment system to maintain at least a 0.15 inch of water vacuum within the secondary containment provides an adequate test of the operation of the reactor building isolation valves, leakage tightness of the reactor building, and performance of the standby gas treatment system. The testing of reactor building automatic ventilation system isolation valves in accordance with Technical Specification 4.6.E demonstrates the operability of these valves. In addition, functional testing of initiating sensors and associated trip channels demonstrates the capability for automatic actuation. Periodic testing gives sufficient confidence of reactor building integrity and standby gas treatment system performance capability. | |||
Amendment No. 4-24, 444, 2-341 169}} |
Revision as of 20:47, 11 November 2019
ML12331A290 | |
Person / Time | |
---|---|
Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
Issue date: | 11/20/2012 |
From: | Wamser C Entergy Nuclear Operations |
To: | Document Control Desk, Office of Nuclear Reactor Regulation |
References | |
BVY 12-078 | |
Download: ML12331A290 (9) | |
Text
Entergy Nuclear Operations, Inc.
Vermont Yankee 320 Governor Hunt Rd.
Vernon, VT SPEntergy 802-257-7711 Christopher J. Wamser Site Vice President BVY 12-078 November 20, 2012 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001
SUBJECT:
Technical Specifications Proposed Change 297, Supplement 2 Response to Request for Additional Information Vermont Yankee Nuclear Power Station Docket No. 50-271 License No. DPR-28
REFERENCES:
- 1. Letter, Entergy Nuclear Operations, Inc. to USNRC, "Technical Specification Proposed Change No. 297 Suppression Chamber-Drywell Leak Rate Test Surveillance Frequency Change," BVY 12-005, dated February 1, 2012
- 2. Letter, Entergy Nuclear Operations, Inc. to USNRC, "Technical Specification Proposed Change No. 297, Supplement 1, Response to Request for Additional Information," BVY 12-055, dated August 7, 2012
Dear Sir or Madam:
In Reference 1, Entergy Nuclear Operations, Inc. (Entergy) submitted a request, as supplemented by Reference 2, for an amendment to the renewed facility operating license Technical Specifications (TS) for Vermont Yankee requesting a change to the TS related to the drywell to suppression chamber vacuum breakers. This letter provides supplemental information to address a request for additional information (RAI) received on November 1, 2012 and discussed on a teleconference held November 1, 2012.
Attachment 1 to this submittal provides Entergy's response to the RAI and Attachment 2 provides revised TS and TS Bases pages reflecting the changes proposed to address NRC questions. The TS Bases page is provided for information only.
This supplement to the original license amendment request does not change the scope or conclusions in the original application, nor does it change Entergy's determination of no significant hazards consideration.
There are no new regulatory commitments being made in this letter.
MV]
BVY 12-078 / Page 2 of 2 Should you have any questions concerning this letter or require additional information, please contact Robert Wanczyk at 802-451-3166.
I declare under penalty of perjury that the foregoing is true and correct. Executed on November 20, 2012.
Sincerely, CJW/plc Attachments: 1. Response to Request for Additional Information
- 2. Retyped Technical Specification and Bases Pages cc: William M. Dean Regional Administrator, Region 1 U.S. Nuclear Regulatory Commission 2100 Renaissance Blvd, Suite 100 King of Prussia, PA 19406-2713 Mr. Richard V. Guzman, Project Manager Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop O-8-C2 Washington, DC 20555 USNRC Resident Inspector Entergy Nuclear Vermont Yankee, LLC 320 Governor Hunt Road Vernon, Vermont 05354 Ms. Elizabeth Miller Commissioner Vermont Department of Public Service 112 State Street - Drawer 20 Montpelier, Vermont 05620-2601
BVY 12-078 Docket 50-271 Attachment 1 Proposed Change 297, Supplement 2 Response to Request for Additional Information
.1 BVY 12-078 / Attachment 1 / page 1 of 1 Response to Request for Additional Information (RAI)
RAI The proposed Technical Specification (TS) change would allow the drywell-to-suppression chamber leak rate surveillance test to be performed any time during an operating cycle (OC) of 18 months as opposed to performing the test during every refueling outage (RFO). The proposed change would therefore allow the test frequency to be revised from a current frequency of 18 months to anywhere up to 36 months. In case the test is not performed during an RFO, and the plant is brought to power, it could allow entering a MODE where containment integrity is required without having met the surveillance requirement (SR). This would be in conflict with SR 4.0.1 which states:
SRs shall be met during the modes or other specified conditions in the Applicability for individual LCOs, unless otherwise stated in the SR. Failureto meet a Surveillance, whether such failure is experienced during the performance of the Surveillance or between performances of the Surveillance, shall be failure to meet the LCO. Failureto perform a Surveillance within the specified frequency shall be failure to meet the LCO except as provided in SR 4.0.3. Surveillances do not have to be performed on inoperableequipment or variablesoutside specified limits.
Please explain how the proposed TS change ensures that the SR is met consistently every 18 months.
Note that in Standard Technical Specification (STS) (NUREG-1433, Volume 1, Revision 3),
the frequency for SR 3.6.1.1.2 is 18 months and has to be met in Modes 1, 2, and 3. The test frequency prevents from entering from MODE 5 to Mode 1, 2, or 3 without verifying containment integrity.
Response
Entergy agrees with this observation and proposes to revise the specified frequency of the drywell-to-suppression chamber leak rate test to once every 18 months, consistent with SR 3.6.1.1.2 in NUREG-1433 "Standard Technical Specifications General Electric Plants, BWR/4."
Attachment 2 provides revised TS and TS Bases pages reflecting this change.
BVY 12-078 Docket 50-271 Attachment 2 Proposed Change 297, Supplement 2 Retyped Technical Specification and Bases Pages
VYNPS 3.7 LIMITING CONDITIONS FOR 4.7 SURVEILLANCE REQUIREMENTS OPERATION at normal cooldown rates if the torus water temperature exceeds 120*F.
- e. Minimum Water Volume
- 68,000 cubic feet
- f. Maximum Water Volume
- 70,000 cubic feet
- 2. Primary containment 2. Primary Containment integrity shall be Surveillances maintained at all times when the reactor is a. The primary containment critical or when the integrity shall be reactor water temperature demonstrated as required is above 212°F and fuel is by the Primary in the reactor vessel Containment Leakage Rate except while performing Testing Program (PCLRTP).
low power physics tests at atmospheric pressure at b. Once every 18 months, a power levels not to exceed drywell to suppression chamber leak rate test 5 Mw(t).
shall demonstrate that with an initial
- 3. If a portion of a system that is considered to be differential pressure of not less than 1.0 psi, an extension of primary containment is to be the differential pressure opened, isolate the decay rate shall not affected penetration flow exceed the equivalent of path by use of at least the leakage rate through one closed and deactivated a 1-inch orifice. Should there be two consecutive automatic valve, closed manual valve or blind test failures the test flange. frequency shall be changed to once every 9 months until two
- 4. Whenever primary containment integrity is consecutive tests pass.
required:
- 3. (Blank)
- a. The leakage rate from
- 4. In accordance with the any one main steam isolation valve (MSIV) PCLRTP, verify that the shall not exceed 62 following leakage rates are within acceptable limits:
scfh at 44 psig (Pa);
- b. The combined leakage a. The leakage rate through rate from the main each MSIV; steam pathways shall not exceed 124 scfh at b. The combined leakage rate for the main steam 44 psig (Pa); and pathways; and
- c. The combined leakage rate from the secondary c. The combined leakage rate for the secondary containment bypass pathways shall not containment bypass exceed 5 scfh at 44 pathways.
psig (Pa).
Amendment No. &G, 4-5-2-, 4-6-, 4-74, 2-2-3 147
VYNPS I
3.7 LIMITING CONDITIONS FOR 4.7 SURVEILLANCE REQUIREMENTS OPERATION line is verified to be closed and conditions required by 3.7.D.2 are met.
- 6. Pressure Suppression 6. Pressure Suppression Chamber - Drywell Vacuum Chamber - Drywell Vacuum Breakers Breakers
- a. When primary a. Periodic Operability containment is Tests required, all suppression chamber Operability testing
- drywell vacuum of the vacuum breakers shall be breakers shall be in operable except accordance with during testing and Specification 4.6.E as stated in and within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> Specifications after any discharge 3.7.A.6.b and c, of steam to the below. Suppression suppression chamber chamber - drywell from the vacuum breakers safety/relief valves shall be considered and within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> operable if: following an operation that (1) The valve is causes any of the demonstrated vacuum breakers to to open fully open. Operability with the of the corresponding applied force position switches at all valve and position positions not indicators and exceeding alarms shall be that verified monthly and equivalent to following any 0.5 psi maintenance.
acting on the suppression b. Refueling Outage chamber face Test of the valve disk. (1) All suppression (2) The valve can chamber -
be closed by drywell gravity, when vacuum released breaker after being position opened by indication remote or and alarm manual means, systems shall to within not be calibrated greater than and the functionally equivalent of tested.
0.05 inch at all points (2) Deleted along the seal surface of the disk.
Amendment No. 1-14, 2-31 149
VYNPS 3.7 LIMITING CONDITIONS FOR 4.7 SURVEILLANCE REQUIREMENTS OPERATION (3) The position alarm system will annunciate in the control room if the valve opening exceeds the equivalent of 0.05 inch at all points along the seal surface of the disk. (3) Deleted
- b. Up to two (2) of the ten (10) suppression chamber - drywell vacuum breakers may be determined to be inoperable provided 7. Oxygen Concentration that they are secured, or known to The primary containment be, in the closed oxygen concentration shall position. be measured and recorded on a weekly basis.
- c. Reactor operation may continue for fifteen (15) days provided that at least one position alarm circuit for each vacuum breaker is operable and each suppression chamber
- drywell vacuum breaker is physically verified to be closed immediately and daily thereafter.
- 7. Oxygen Concentration
- a. The primary containment atmosphere shall be reduced to less than 4 percent oxygen by volume with nitrogen gas while in the RUN MODE during the time period:
i.From 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after thermal power is greater than 15% rated thermal power following startup, to Amendment No. 4-1-4, 4-2-8.,2--2f 2-3-, 150
VYNPS BASES: 4.7 (Cont'd)
Every 18 months, a leak rate test shall be performed to verify that significant leakage flow paths do not exist between the drywell and suppression chamber. The drywell pressure will be increased by at least 1 psi with respect to the suppression chamber pressure and held constant. The 2 psig set point will not be exceeded. The subsequent suppression chamber pressure transient (if any) will be monitored with a sensitive pressure gauge. If the drywell pressure cannot be increased by 1 psi over the suppression chamber pressure it would be because a significant leakage path exists; in this event the leakage source will be identified and eliminated before power operation is resumed. If the drywell pressure can be increased by 1 psi over the suppression chamber the rate of change of the suppression chamber pressure must not exceed a rate equivalent to the rate of leakage from the drywell through a 1-inch orifice. In the event the rate of change exceeds this value then the plant will be shut down, if operating, the source of leakage will be identified and addressed before power operation is resumed. Two consecutive test failures, however, would indicate unexpected primary containment degradation; in this event, increasing the frequency to once every 9 months is required until the situation is remedied as evidenced by passing two consecutive tests.
The drywell-suppression chamber vacuum breakers are exercised in accordance with Specification 4.6.E, following termination of discharge of steam into the suppression chamber from the safety/relief valves and following any operation that causes the vacuum breakers to open. This monitoring of valve operability is intended to assure that valve operability and position indication system performance does not degrade between refueling inspections.
When a vacuum breaker valve is exercised through an opening-closing cycle, the position indicating lights are designed to function as follows:
Full Closed 2 White - On (Closed to <0.050" open)
Open 2 White - Off
(>0.050" open to full open)
Experience has shown that a weekly measurement of the oxygen concentration in the primary containment assures adequate surveillance of the primary containment atmosphere.
B. and C. Standby Gas Treatment System and Secondary Containment System Initiating reactor building isolation and operation of the standby gas treatment system to maintain at least a 0.15 inch of water vacuum within the secondary containment provides an adequate test of the operation of the reactor building isolation valves, leakage tightness of the reactor building, and performance of the standby gas treatment system. The testing of reactor building automatic ventilation system isolation valves in accordance with Technical Specification 4.6.E demonstrates the operability of these valves. In addition, functional testing of initiating sensors and associated trip channels demonstrates the capability for automatic actuation. Periodic testing gives sufficient confidence of reactor building integrity and standby gas treatment system performance capability.
Amendment No. 4-24, 444, 2-341 169