ML20195H604
| ML20195H604 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 11/16/1998 |
| From: | Salas P TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20195H608 | List: |
| References | |
| TVA-SQN-TS-98, TVA-SQN-TS-98-0, NUDOCS 9811240049 | |
| Download: ML20195H604 (8) | |
Text
_
e Tennessee Valley Authority Post office Box 2000, Soddy-Daisy, Tennessee 37179-2000 l
November 16, 1998 TVA-SQN-TS-98-06 10 CFR 50.90 U.S.
Nuclear Regulatory Commission ATTN:
Document Control Desk Washington, D.
C.
20555 i
Gentlemen:
In the Matter of
)
Docket Nos. 50-327 Tennessee Valley Authority
)
50-328 SEQUOYAH NUCLEAR PLANT (SQN) - UNITS 1 AND 2 - TECHNICAL SPECIFICATION (TS) CHANGE NO. 98-06
" EMERGENCY DIESEL GENERATOR (D/G) LOAD SEQUENCE TIMER AND LOCKOUT REAY SURVEILLANCE REQUIREMENT (SR) CHANGES" In accordance with the provisions of 10 CFR 50.4 and 50.90, TVA is submitting a request for an amendment to SON's I
licenses DPR-77 and 79 to change the TSs for Units 1 and 2.
The proposed change revises the emergency D/G SRs to:
/
(1) add a note that allows the SR to be performed in Modes 1, 2,
3 or 4, if the associated components are already out-of-
)g 7g service for testing or maintenance, and (2) remove the SR that verifies certain lockout features prevent D/G starting.
TVA has determined that there are no significant hazards considerations associated with the proposed change and that the change is exempt from environmental review pursuant to the provisions of 10 CFR 51.22 (c) (9).
The SQN Plant Operations Review Committee and the SON Nuclear Safety Review Board have reviewed this proposed change and determined that operation of SON Units 1 and 2, in accordance with the proposed change, will not endanger the health and safety of 9811240049 981116 PDR ADOCK 05000327 p
U.S. Nuclear Regulatory Commission Page 2 November 16, 1998 the public.
Additionally, in accordance with 10 CFR
- 50. 91 (b) (1), TVA is sending a copy of this letter to the Tennessee State Department of Public Health.
1 to this letter provides the description and evaluation of the proposed change.
This includes TVA's determination that the proposed change does not involve a significant hazards consideration, and is exempt from environmental review. contains copies of the i
appropriate TS pages from Units 1 and 2 marked-up to show the l
proposed change. forwards the revised TS pages l
for Units 1 and 2 which incorporate the proposed change.
TVA requests that approval be provided to support the Unit 2 Cycle 9 refueling outage, currently scheduled to start l
mid-April 1999, and that the revised TS be made effective l
within 45 days of NRC approval.
If you have any questions about this change, please telephone me at (423) 843-7170 or l
J.
D.
Smith at (423) 843-6672.
i l
Sincere y,
-y edr as Licensing and Industry Affaire Manager Subscribed p+pd sworn toJ efore ye O this,$
day of,/,/f)//W (t])? )
l -
b J/
J / l' $
1 4 )
\\
Notaff Publ'ic' '
~/
('
b My Commission Expires October 9, 2002 l
Enclosures cc:
See page 3 l
U.S. Nuclear Regulatory Commission Page 3 November 16, 1998 cc (Enclosures):
Mr. R.
W. Hernan, Project Manager Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852-2739 Mr. Michael H. Mobley, Director (w/o Enclosures)
Division of Radiological Health Third Floor L&C Annex 401 Church Street Nashville, Tennessee 37243-1532 NRC Resident Sequoyah Nuclear Plant 2600 Igou Ferry Road Soddy-Daisy, Tennessee 37379-3624 Regional' Administrator-U.S. Nuclear Regulatory Commission Region II Atlanta Federal Center 61 Forsyth St.,
SW, Suite 23T85 Atlanta, Georgia 30303-3415
ENCLOSURE 1 TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT (SQN)
UNITS 1 and 2 DOCKET NOS 327 AND 328 PROPOSED TECHNICAL SPECIFICATION (TS) CHANGE TS-98-06 DESCRIPTION AND EVALUATION OF THE PROPOSED CHANGE I.
DESCRIPTION OF THE PROPOSED CHANGE TVA proposes to modify the Sequoyah Nuclear Plant (SQN)
Units 1 and 2 TSs by revising Surveillance Requirements (SRs) 4.8.1.1.2.d.10 and 4.8.1.1.2.d.11.
This revision will:
(1) add a note that allows the SR associated with verifying the automatic load sequencer timer setpoints to be performed in Modes 1, 2, 3 or 4, if the associated equipment is out-of-service for maintenance or testing, and (2) remove from TS the SR that verifies certain lockout features prevent diesel generator (D/G) starting only when required.
These changes are described as follows:
SR 4.8.1.1.2.d.10 - Add a note that allows the SR to be performed in Modes 1, 2,
3 or 4, if the associated equipment is out-of-service for maintenance or testing.
SR 4.8.1.1.2.d.11 - Delete this SR which verifies certain D/G lockout features prevent D/G starting only when required.
II.
REASON FOR THE PROPOSED CEANGE TVA proposes to allow verifying the automatic load sequencer timers are within i 5 percent of their design setpoints to be performed at any operational mode if coupled with existing testing or maintenance.
This change allows testing, currently required to be performed during outages, to be moved to periods with lighter, less complex maintenance schedules and more efficient use of existing limiting condition for operation (LCO) allowed outage time.
The change to delete SR 4.8.1.1.2.d.11 from TSs is consistent with NUREG-1431, and is being proposed to remove items inconsistent with normal TS content in order to simplify TSs.
El-1
l III.
SAFETY ANALYSIS The standby D/Gs serve as the plant emergency standby alternating current (ac) power source.
They are designed, installed, and tested to requirements necessary to assure their availability.
The D/Gs consist of four self-contained, water-cooled, automatic-starting, diesel engine driven, and stationary electric generators.
Two D/Gs in the same train are required to mitigate a design basis event (DBE) in one unit; redundancy for single failure is provided by maintaining four D/Gs in ready condition for automatic start.
The D/Gs are designed for automatic connection to 6.9-kV shutdown boards with automatic load sequencer timers adding large loads to the boards in the appropriate sequence so that the D/Gs do not overload during the process.
The D/Gs have various protective devices installed to shutdown a D/G automatically to prevent heavy damage in the event of a system malfunction.
As described in Final Safety Analysis Report (FSAR) Section 8.3.1.1, these devices are operative only during the exercise mode of operation, with the exception of the generator differential relay and the engine overspeed switch.
Calibration of the time delay relays, associated with automatic load sequence timers, may defeat certain functions in the downstream equipment energized by the timer, which may require entry into LCOs associated with the function.
However, the time required to perform the calibration is typically a small fraction of the LCO period.
Maintenance and testing functions typically require periodic entry into these same LCOs.
Coupling the calibrations with existing maintenance or testing LCO allowed outage time does not increase the unavailability of the equipment.
It does allow the calibrations to be done at a time when the maintenance schedule is less complex and less hurried, inherently reducing the potential for human error and more efficient use of LCO allowed outage time.
This is consistent with NRC Generic Letter 91-04, which states, "The Staff concludes that the TS need not restrict surveillances as only being performed during shutdown.
Nevertheless, safety dictates that when refueling interval surveillances are being performed during power operation licensees give proper regard for their effect on safe operation of the plant."
Standard TSs recognize this issue in the reviewers note concerning mode restrictions.
They allow plant specific removal of El-2
mode restrictions based on meeting three criteria that performance of the SR will not:
Render any safety system or component inoperable.
This criteria is met by doing the work coup! d with existing out-of-service conditions.
Cause perturbations to any of the electrical distribution systems that could result in a challenge to steady state operation or to plant safety systems.
Calibration of the time delay relays, associated with the load sequence timers, only affects downstream equipment, which will already be out-of-service for testing or maintenance activities.
Therefore, there will be no challenge to steady state operation or to plant safety systems.
Cause or result in an anticipated operational occurrence with attendant challenge to plant safety systems.
The work will be coupled with existing out-of-service conditions so it will not cause or result in an anticipated operational occurrence.
Removal of the requirement for verifying certain D/G lockout features that prevent D/G starting only when required is consistent with standard TSs (NUREG-1431).
The surveillances implementing this SR verify that the D/G will not start if one or more of the emergency trips are active.
This SR verifies an equipment protection function.
The function is nonsafety related; therefore, it does not meet the test for inclusion in TSs in accordance with 10 CFR 50.36 criteria.
The equipment affected is not:
Used to detect or indicate a significant abnormal degradation of the reactor coolant system boundary.
A process variable, design feature or operating restriction that is an initial condition to a design basis accident (DBA).
A structure, system or component that is part of the primary success path and which functions or actuates to mitigate a DBA.
A structure, system or component, which operating experience er probabilistic safety assessment has shown to be significant to the public health and safety.
)
El-3
4 This SR was removed from TSs in the development of the standard TSs (NUREG-1431).
It was removed because the function was only for equipment protection and the requirement was not contained in the TSs of other recently licensed plants at that time.
The functions will remain as described in FSAR Section 8.3.1.1.
IV.
NO SIGNIFICANT HAZARDS CONSIDERATION DETERMINATION TVA has concluded that operation of SON Units 1 and 2, in accordance with the proposed change to the TSs, does not involve a significant hazards consideration.
TVA's conclusion is based on its evaluation, in accordance with 10 CFR 50. 91(a) (1), of the three standards set forth in 10 CFR 50.92(c).
A.
The proposed amendment does not involve a significant increase in the probability or consequences of an accident previously evaluated.
The probability of occurrence or the consequences for an accident or malfunction of equipment is not increased by this request.
The proposal does not alter the way any structure, system or component functions, does not modify the manner in which the plant is operated.
,nd does not alter equipment out-of-service tin This request does not degrade the ability of the ?<G or equipment downstream of the load sequencers to perform their intended function.
Deleting the surveillance of a nonsafety-related equipment protection function from TS likewise does not change the probability or consequences of analyzed accident scenarios.
Dose consequences remain unchanged by this request.
B.
The proposed amendment does not create the possibility of a new or different kind of accident from any accident previously evaluated.
A possibility for an accident or malfunction of a different type than any evaluated previously in SQN's FSAR is not created; nor is the possibility for an accident or malfunction of a different type.
The proposal does not alter the way any structure, system or component functions and does not modify the manner
{
in which the plant is operated.
t i
l El-4 I
C.
The proposed amendment does not involve a significant reduction in a margin of safety.
i The margin of safety has not been reduced since the test methodologies are not being changed and LCO allowed outage times are not being changed.
Deleting the surveillance of a nonsafety-related equipment i
protection function from TS likewise does not reduce the margin of safety.
The results of accident analysis remain unchanged by this request.
V.
ENVIRONMENTAL IMPACT CONSIDERATION The proposed change does not involve a significant hazards consideration, a significant change in the types of or significant increase in the amounts of any effluents that may be released offsite, or a significant increase in individual or cumulative occupational radiation exposure.
Therefore, the proposed change meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22 (c) (9).
Therefore, pursuant to 10 CFR 51.22(b), an environmental assessment of the proposed change is not required.
l El-5