ML20212C252
| ML20212C252 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 09/17/1999 |
| From: | Clifford J NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20212C168 | List: |
| References | |
| NUDOCS 9909210196 | |
| Download: ML20212C252 (8) | |
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NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555 4 001 4 * * * * *,o 9
VERMONT YANKEE NUCLEAR POWER CORPORATION DOCKET NO. 50-271 VERMONT YANKEE NUCLEAR POWER STATION AMENDMENT TO FACILITY OPERATING LICENSE Amendment No.175 License No. DPR-28 1.
The Nuclear Regulatory Commission (the Commission) has found that:
A.
The application for amendment filed by the Vermont Yankee Nuclear Power Corporation (the licensee) dated May 5,1999, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commission's rules and regulations set forth in 10 CFR Chapter I; B.
The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C.
There is reasonable assurance: (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commission's regulations; D.
The issuance of this amendment will not be inimical to the common defense and
~
security or to the health and safety of the public; and E.
The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commission's regulations and all applicable requirements have been satisfied.
9909210196 990917 PDR ADOCK 05000271 P
. 2.
Accordingly, the license is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment, and paragraph 3.B of Facility Operating License No. DPR 28 is hereby amended to read as follows:
(B)
Igqhnical Soecifications The Technical Specifications contained in Appendix A, as revised through j
Amendment No. 175, are hereby incorporated in the license. The licensee shall operate the facility in accordance with the Technical Specifications.
3.
This license amendment is effective as of its date of issuance and shall be implemented within 30 days.
FOR THE NUCLEAR REGULATORY COMMISSION J mes W. Cliffor, Chief, Section 2 Project Directorate i Division of Licensing Project Management Office of Nuclear Reactor Regulation
Attachment:
Changes to the Technical Specifications Date of issuance:
September 17, 1999
F ATTACHMENT TO LICENSE AMENDMENT NO.175 FACILITY OPERATING LICENSE NO. DPR-28 DOCKET NO. 50-271 Replace the following pages of the Appendix A Technical Specifications with the attached revised pages. The revised pages are identified by amendment number and contain marginal lines indicating the areas of change.
Remove insert 92 92 93 93 94 94 97 97 98 98 Y
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VYNPC 3.4 LIMITING CONDITIONS FOR 4.4 SURVEILLANCE REQUIREMENTS OPERATION 3.4 REACTOR STANDBY LIQUID CONTROL 4.4 REACTOR STANDBY LIQUID CONTROL SYSTEM SYSTEM Applicability-Applicability:
Applies to the operating status Applies to the periodic testing of the Reactor Standby Liquid requirement for the Reactor Control System.
Standby Liquid Control System.
Objective:
Objective:
To assure the availability of an To verify the operability of the independent reactivity control Standby Liquid Control System.
mechanism.
Specification:
Specification:
A.
Normal Operation A.
Normal Operation Except as specified in 3.4.B The Standby Liquid Control below, the Standby Liquid System shall be verified Control System shall be operable by:
operable when the reactor mode switch is in either the 1.
Testing pumps and valves "Startup/ Hot Standby" or in accordance with "Run" position, except to Specification 4.6.E.
A allow testing of minimum flow rate of instrumentation associated 35 gpm at 1275 psig with the reactor mode switch shall be verified for interlock functions each pump.
l provided:
2.
Verifying the continuity 1.
Reactor coolant of the explosive charges temperature is less than at least monthly.
or equal to 212' F; In addition, at least once 2.
All control rods remain during each operating cycle, fully inserted in core the Standby Liquid Control cells containing one or System shall be verified more fuel assemblies; operable by:
and 3.
Testing that the setting 3.
No core alterations are of the pressure relief in progress, valves is beLove. 1400 and 1490 psig.
4.
Initiating one of the standby liquid control o
loops, excluding the l
primer chamber and inlet j
l fitting, and verifying l
that a flow path from a pump to the reactor vessel is available.
Both loops shall be tested over the course oftwooperatingcyci]s.
Amendment No. 444, 448, 444, 175 92 1
VYNPS 34 LIVITING CONDITIONS FOR 4.4
'_'R'/EILLANCE REQUIFEMENTS OPERATION 5.
Testing the new trigger assemblies by installing one of the assemblies in the test block and firing it using the installed circuitry.
Install the unfired assemblies, taken from the same batch as the fired one, into the explosion valves.
6.
Recirculating the borated solution.
B.
Operation with Inoperable B.
Operation with Inoperable Components Components From and after the date that When a component becomes a redundant component is inoperable, its redundant made or found to be component shall be or shall inoperable, reactor have been demonstrated to be operation is permissible operable within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
during the succeeding seven days unless such component is sooner made operable.
C.
Standby Liquid Control System C.
Standby Liquid Control System Tank - Borated Solution Tank - Borated Solution At all times when the Standby Liquid Control System is required to be operable, the following conditions shall be met:
1.
The net volume versus 1.
The solution volume in concentration of the the tank and temperature sodium pentaBbrate in the tank and suction solution in the standby piping shall be checked liquid control tank at least daily.
shall meet the requirements of Figute 3.4.1.
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Amendment No. 443, 444, 444, 175 93 r
r c
VYNPS 3.4 LIMITING CONDITIONS FOR 4.4 SURVEILLANCE REQUIREMENTS OPERATION 2.
The solution 2.
Sodium pentaborate temperature, including concentration shall be that in the pump suction determined at least once piping, shall be a month and within maintained above the 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> following the curve shown in addition of water or Figure 3.4.2.
boron, or if the solution temperature 3.
The combination of drops below the limits Standby Liquid Control specified by System pump flow rate, Figure 3.4.2.
boron concentration, and boron enrichment shall satisfy the following 3.
The boron-10 enrichment relationship for the of the borated solution Standby Liquid Control required by Specification System to be considered 3.4.C.3 shall be tested operable:
and verified once per operating cycle.
- x - x - x -
21 86 H
13 19.8 where:
C=
the concentration of sodium pentaborate solution (weight percent) in the Standby Liquid Control System tank E=
the boron-10 enrichment (atom percent) of the sodium pentaborate solution 0=
35 gpm M251
-- = a constant (the M
ratio of mass of water in the reference plant compared to VY) j D.
If Specification 3.4.A or B is not met, an orderly shutdown shall be initiated and the reactor shall be in the cold shutdown condition within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
E.
If Specification 3.4.C is not met, action shall be immediately initiated to correct the deficiency.
If at the end of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> the system has not been restored to full operability, then a shutdown shall be initiated with the reactor in cold shutdown within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of initial discovery.
Amendment No. 44, 44, 443, 175 94
E i
i VYNPS
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BASES:
3.4 & 4.4 REACTOR STANDBY LIQUID CONTROL SYSTEM A.
Normal Operation The design objective of the Reactor Standby Liquid Control System is to provide the capability of bringing the reactor from full power to a cold, xenon-free shutdown assuming that none of the withdrawn control i
rods can be inserted. To meet this objective, the Standby Liquid l
Control System is designed to inject a quantity of boron which produces a concentration of 800 ppm of natural boron in the reactor core in less than 130 minutes. An 800 ppm natural boron concentration in the reactor core is required to bring the reactor from full power to a 5%
Ak suberitical condition._ An additional margin (25% of boron) is added for possible imperfect mixing of the chemical solution in the reactor water. A minimum quantity of 3850 gallons of solution having a 10.1%-
natural sodium pentaborate concentration is required to meet this l
shutdown requirement.
The time requirement (138 minutes) for insertion of the boron solution was selected to override the rate of reactivity insertion due to cooldown of the reactor following the xenon poison peak.
For a required minimum pumping rate of 35 gallons per minute, the maximum net storage volume of the boron solution is established as 4830 gallons.
In addition to its original design basis, the Standby Liquid Control System also satisfies the requirements of 10CFR50.62 (c) (4) on anticipated transients without scram (ATWS) by using enriched boron.
The ATWS rule adds hot shutdown and neutron absorber (i.e., boron-10) injection rate requirements that exceed the original Standby Liquid l
Control System design basis.
However, etanges to the Standby Liquid Control System as a result of the ATWS rule have not invalioated the original design basis.
With the reactor mode switch in the "Run" or "Startup/ Hot Standby" position, shutdown capability is required. With the mode switch in
" Shutdown," control rods are not able to be withdrawn since a control rod block.is applied. This provides adequate controls to ensure that the reactor remains suberitical. With the mode switch in " Refuel,"
only a single control rod can be withdrawn from a core cell containing fuel assemblies.
Determination of adequate shutdown margin by Specification 3.3.A ensures that the reactor will not become critical.
Therefore, the Standby Liquid Control System is not required to be operable when only a single control rod can be withdrawn.
Pump operability testing (by recirculating demineralized water to the l
l test tank)in accordance with Specification 4.6.E is adequate to detect j
L if failures have occurred.
Flow, relief valve, circuitry, and trigger i
j assembly testing at the prescribed-intervals assures a high reliability of system operation capability.
Recirculation of the borated solution is done during each operating cycle to ensure one suction line from the boron tank is clear. In addition, at least once during each operating
)
cycle, one of the standby liquid control loops will be initiated to l
verify that a flow path from a pump to the reactor vessel is available by pumping demineralized water into the reactor vessel.
B.
Operation With Inoperable Components Only one of the two standby liquid control pumping circuits is needed for proper operation of the system.
If one pumping circuit is found to Amendment No. MG, - M4, 4a, 175 97 i
l
7, s
VYNPS 1
l be, inoperable, there is no immediate threat to shutdown capability, and reactor operation may continue while repairs are being made.
Assurance i
I that the system will perform its intended function is obtained from the results of the pump and valve testing performed in accordance with ASME Section XI requirements.
Whenever one redundant component is inoperable, the potential for extended operation with two subsystems inoperable is reduced by requiring that the redundant component is l
tested within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
C.
Standby Liquid Control System Tank - Borated Solution The solution saturation temperature varies with the concentration of sodium pentaborate.
The solution shall be kept at least 10'F above the saturation temperature to guard against boron precipitation.
The 10*F margin is included in Figure 3.4.2.
Temperature and liquid level l
alarms for the system are annunciated in the Control Room.
Once the solution has been made up, boron concentration will not vary o
unless more boron or water is added.
Level indication and alarm indicate whether the solution volume has changed which might indicate a possible solution concentration change.
Considering these factors, the test interval has been established.
Sodium pentaborate concentration is determined within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> following the addition of water or boron, or if the solution temperature drops below specified limits.
The 24-hour limit allows for 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> of mixing, subsequent testing, and notification of shift i
persennel.
l Boron concentration, solution temperature, and volume are checked on a frequency to assure a high reliability of operation of the system should it ever be required.
Isotopic tests of the sodium pentaborate are performed periodically to ensure that the proper boron-10 atom percentage is being used.
I 10CFR50.62 (c) (4) requires a Standby Liquid Control System with a minimum flow capacity and boron content equivalent to 86 gpm of 13 weight percent natural sodium pentaborate solution in the 251-inch reactor pressure vessel reference plant.
Natural sodium pentaborate solution is 19.8 atom percent boron-10.
The relationship expressed in Specification 3.4.C.3 also contains the ratio M251/M to account for the difference in water volume between the reference plant and Vermont Yankee.
(This ratio of masse-is 628,300 lbs./401,247 lbs.)
To comply with the ATWS rule, the combination of three Standby Liquid Control System parameters must be considered: boron concentration, Standby Liquid Control System pump flow rate, and boron-10 enrichment.
Fixing the pump flow rate in Specification 3.4.C.3 at the minimum flow rate of 35 gpm conservatively establishes a system parameter that can be used in satisfying the ATWS requirement, as well as the original system design basis.
If the product of the expression in Specification 3.4.C.3 is equal to or greater than unity, the Standby Liquid Control System satisfies the requirements of 10CFR50.62 (c) (4).
y.
s Amendment No. 44G, 448, 175 98