ML20237D371
| ML20237D371 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 12/21/1987 |
| From: | Kuncl L NEBRASKA PUBLIC POWER DISTRICT |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| Shared Package | |
| ML20237D373 | List: |
| References | |
| NUDOCS 8712230231 | |
| Download: ML20237D371 (5) | |
Text
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P O BOX 499. COLUMBUS NEBRASKA 686014439 y
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Nebraska Publ.ic Power Distr. t ic mEmoNE me essi M_
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t, December 21, 1987
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U.S. Nuclear Regulatory Commission 1
Washington, D.C. 20555 L
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'l Attention:
Document Control Desk
Subject:
Expedited Technical Specification Change Proposed Change No. 56 4
Reactor Building isolation System Functional Testing Cooper Nuclear Station Docket No. 50-298, DPR-46, ;
I Based upon discussions with the District s NRC Pnject M[ nager, this letter is wr!tten to request an expeditious change to the Coopty Nuclear Station Technical Specifications to change the sus /eillance' trequpcy of the functhnal test of the Reactor Building isolation logic to once 'every 18 months.
Cooper Nuclear Station Technical Specifications 4.2. A a'nrJ 4.2.D.2 state 1 Nt the logic systems for the Reactor Building Heating and Ventilation and Reactor -
Building isolation and Control Systems are to be functionally tested once every ' i six (6) months.
Specification 4.2. A tests the low reactor water level and high y
drywell pressure initiation signals for Reactor Building isolation and.
Specification 4.2.D.2 tests the ventilation exhaust plenum high radiation bolation signal.
Performing these functional tests isolates the Reactor Building ventilation supply from the outsite environment including ventilation to the Reactor Recirculation Motor Generator (RRMG) sets.
To minimize the resuidng temperature rises in the RRMG's, the tests are usually performed during periods of low recirculation pump speed operation or when the pumps are 1
secured (i.e., during periods of reactor shutdown or in outages).
Records show that during the history of the plant the subject tests were performed twice during power operation (both tests were performed in the 1970's).
The current lengthy continuous run time of the plant, combined with the six-month surveillance requirement coming due on January 2,1988, will necessitate performing the test at power.
Plant manacy! ment has reviewed the RRMG set temperature data for the two tests conducted at power and have concluded that RRMG set trinping on high temperature is a distinct possibility.
A trip of both RRMG sets would result in operation in natural circulation in the instability region on the power-flow curve. Specification 3.3 F.1 precludes attempting to restart a recirculation pump while in natural circulation at greater than 1 percent of rated thermal power.
A plant shutdown would be required in it is condition.
The primary reason for this expedited Technical SpWificatici change request O
is to extend the surveillance frequency of the retutpr building isolation and d-QP related iogic functional tests to once every 18 months, consistent with Standard Technical Specifications.
This will allow these tests to be performed fe,c,l [ W/C8'#
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U.S. Nuclear Regulatory Commisrion Page 2 j
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i exclusively during periods of plant shutdown and avoid the possibility of an I
unnecessary plant shatdown resulting from tripping both R RM G sets.
In I
addition, a review of other surveillance requirements with intervals less than 18 months will be made against the Standard Technical Specifications to identify similar instances.
Any proposed Technical Specifications changes that i
result from this review will be submitted at a later date.
Mr H. R. Borchert, Nebraska Department of Health, has been notified by telephone of the circumstances at Cooper Nuclear Station, and is being copied on this letter.
This change has been reviewed by the necessary Safety Revies Committees and payment of $150 is submitted in accordance with 10CFR170.12.
In addition to the signed original, 37 copies of this submittal are also submitted for your l
use.
Copies to the NRC Region IV office and the CNS Resident Inspector are also being sent in accordance with 10C FR50.4(b)(2).
This proposed license amendment involves a change in the installation or use of
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a facility component located within the restricted area as defined in 10C FR, Part 20, and changes in s surveillance re q uire ments.
The District has determined that this amendment involves no significant increase in the amounts, and no significant change in the type, of any effluents that may be released off site, and that there is no significant increase in individual or cumulative occupational radiation exposure.
Accordingly, the District is of the opinion that this amendment would meet the eligibility criteria for categorical exclusion set forth in 10 C F R 51. 22(c)(9).
Pursuant to 10C FR51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with this amendment.
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I Should you have any questions or require additional information, please telep ho ne.
Sincerely, N
L. G. K u n cl Vice-President - Nuclear L G K/grs:m h14/7(56)
Attach ments cc:
H. R. Borchert Nebraska Department of Health N RC Regional Oftke Region IV Arlington, Texas l
N RC Resident Inspector Cooper Nuclear Stat 6n
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1 I-mg-U.S. Nuclear Regulatory Commission -
PageL 3:
. December 21, 1987 i-
. STATE OF NEBRASKA)
)ss PLATTE COUNTY
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L. G. Kuncl, being first duly sworn, deposes and says that he is an authorized ' representative of the Nebraska Public Power - District, a public -
corporation and political subdivision of the State of Nebraska;. that he is duly authorized to submit this request on behalf-of Nebraska Public' Power District; and that the statements contained herein are true to tha best of his knowledge and belief.
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L/ G. Kunct presence and sworn to before me this. fljd ' day of.
Subscr ed m
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NOTARY PUB lL,C GEEE WWY4th W terah COREEN M. KUTA Hy Com a E 4 Ast 4.1 5 1
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REVISED TECHNICAL SPECIFICATIONS FOR REACTOR BUILDING ISOLATION LOGIC FUNCTIONAL TEST Revised Pages 69 78 At Cooper Nuclear Station (CNS) the Reactor Building Isolation and Control System will trip and isolate ventilation systems in the event of a Loss of Coolant Accident inside the drywell or a postulated fuel handling accident on the refuel floor.
At CNS this is a part of the Group VI isolation and is initiated by high drywell pressure, low reactor water level, and high radiation in the Reactor Building ventilation exhaust plenum.
A Group VI isolation performs the following:
1.
Closes the primary containment purge and vent isolation valves.
2.
Trips the Reactor Building ventilation supply and exhaust fans.
3.
Closes the Reactor Building ventilation supply and exhaust valves.
4.
Closes the recirculation motor-generator ventilation isolation valves and trips the Reactor Recirculation Motor Generator set exhaust fans.
5.
Sends a start signal to the standby gas treatment system.
6.
Sends a signal to the logic of the Reactor Equipment Cooling critical loop supply valves.
Various surveillance are performed to verify that the Group VI isolation performs its intended function.
Among these are the logic functional tests performed once every six months to test the relays and contacts from sensor to activated device.
Where practical the action will go to completion; i.e.,
valves wil2 be operated, motors energized, etc.
Performing the logic functional test for the Group VI isolation will close the Reactor Recirculation Motor Generator (RRMG) set ventilation isolation valves and trip the RRMG set exhaust fans.
If the test occurs during plant operation with power being supplied to the recirculation pumps, the resulting temperature rise could trip the RRMG sets resulting in operation in the instability region of the power to flow curve.
Specification 3.3.F.1 precludes attempting to restart a recirculation pump while in natural circulation at greater than 1% of rated thermal power. A plant shutdown would be required in this condition.
To avoid this possibility, the District ii requesting to amend the CNS Technical Specifications to perform the logic system functional tests once
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every 18 months consistent with Specification 4.3.2.2 of the GE Standard Technical Specifications (NUREG-0123 Revision 3).
With a surveillance interval of 18 months, the functional test can always be performed during scheduled outage periods thus avoiding unnecessary transients to plant equipment while operating.
Other logic systems, in addition to the Reactor Building and RRMG set ventilation isolations, are tested either concurrently or separately by the applicable Station Surveillance Procedures that implement these CNS Technical Specifications on pages 69 and 78.
These additional logic systems are also
addressed _by GE Standard Technical Specification 4.3.2.2 or 4.6.5.3.d and it is requested that their functional test surveillance interval be extended to 18 months also.
Specifically, the following changes are requested:
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1.
On page 69 change to once/18 months the functional test frequency for all logic systems in Items No. I through 6.
2.
On page 78, change to once/18 months the functional test frequency for the Standby Gas Treatment Initiation and ' Reactor Building Isolation Logic Systems.
Evaluation of this Revision with Respect to 10CFR50.92 The enclosed Technical Specification Change is judged to involve no significant hazards based upon the following:
1)
Does the proposed license. amendment involve a significant increase in the probability or consequences of an accident previously evaluated?
Evaluation The proposed license amendment will change the logic system functional test interval. of various isolation logic systems from semiannually to once every 18 months. This surveillance frequency is consistent with the guidance provided in the General Electric Standard Technical Specifications and is part of the surveillance requirements that ensures containment operability.
The requirements for primary and secondary containment operability remain as before and current accident analyses and their radiological consequences are as previously evaluated.
The proposed license amendment does not involve a significant increase in the probability or consequences of an accident previously evaluated.
2)
Does the proposed license amendment create the possibility for a new or different kind of accident from any accident previously evaluated?
Evaluation The proposed amendment will change the functional test interval of various isolation logic systems to once every 18 months and does not allow a new or different mode of reactor operation or containment requirements.
This surveillance interval is consistent with NRC guidance contained in NUREG 0123 Revision 3 and will not create the possibility for a new or different kind of accident from any accident previously evaluated.
3)
Does the proposed amendment involve a significant reduction in the margin of safety?
Evaluation The proposed amendment will extend the frequency of several logic system functional tests to an interval consistent with the GE Standard Technical Specifications.
It does not change any operating limits or trip setpoints in the Technical Specifications, so there is no change in the margin of safety.
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