2CAN059303, Application for Amend to License NPF-6,changing TS Table 3.7-1 to Reduce Maximum Allowable Linear Power level-high Trip Setpoints & Revises Associated Bases
| ML20044D035 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 05/07/1993 |
| From: | Yelverton J ENTERGY OPERATIONS, INC. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20044D037 | List: |
| References | |
| 2CAN059303, 2CAN59303, NUDOCS 9305170095 | |
| Download: ML20044D035 (7) | |
Text
-a w..
Entergy Oper:tions, Inc.
Rare 3 B:w 137G
== ENTERGY n-u mm Te! 50MMP22,3 Jerry W. Yelve. ton l
Vcci h h1 D;WW1XC RO May 7,1993 2CAN059303 t
U. S. Nuclear Regulatory Commission Document Control Desk Mail Station Pl-137 Washington, DC 20555
Subject:
Arkansas Nuclear One - Unit 2 4
Docket No. 50-368 License No. hTF-6 Technical Specification Change Request to Reduce Maximum Allowable Linear Power Level-High Trip Setpoints with Inoperable Steam Line Safety Valves Gentlemen:
Attached for your review and approval is a proposed Arkansas Nuclear One - Unit 2 (ANO-2) Technical Specification (TS) change reducing the Maximum Allowable Linear Power Level-High Trip Setpoints associated with Inoperable Steam Line Safety Valves.
The proposed change has been evaluated in accordance with 10CFR50.91(a)(1) using criteria in 10CFR50.92(c) and it has been determined that this change involves no significant hazards considerations. The bases for these determinations are included in the enclosed submittal.
E
'i Entergy Operations requests that the effective date of this change be upon issuance of the j
amendment. This request is neither exigent nor emergency.
!o i
14011G 9305170095 930507 PDR ADDCK 05000368
\\l P
~
^
U. S. NRC May 7,1993 l
2CAN059303 Page 2 Very truly yours, 1
JWY/dbm To the best of my knowledge and belief, the statements contained in this submittal are l
true.
SUBSCRIBED AND SWORN TO before me, a Notary Public in and for Logan County l
and the State of Arkansas, this. fd day of f//w/
,1993.
7 r?AS/ b ) deAfand Notarfpu'blic
~ /
My Commission Expires ///a/ // AWJB y
I Attachments
?
- i
-I e
j U. S. NRC May 7,1993
~
2CAN059303 Page 3 l
cc:
Mr. James L. Milhoan U. S. Nuclear Regulatory Commission Region IV 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-8064 l
NRC Senior Resident Inspector Arkansas Nuclear One - ANO-1 & 2 Number 1, Nuclear flant Road l
Russellville, AR 72801 l
Mr. Roby Bevan NRR Project Manager, Region IV/ANO-1 U. S. Nuclear Regulatory Commission NRR Mail Stop 13-H-3 One White Flint North 11555 Rockville Pike Rockville, MD 20852 Mr. Thomas W. Alexion NRR Project Manager, Region IV/ANO-2 U. S. Nuclear Regulatory Commission NRR Mail Stop 13-H-3 One White Flint North i1555 Rockville Pike Rockville, MD 20852 Ms. Greta Dicus Arkansas Department ofHealth j
Division ofRadiation Control and Emergency Management t
4815 West Markham Street Little Rock, AR 72201 i
l r
I f
i ATTACHMENT 1 E
r 2CAN059303 PROPOSED TECHNICAL SPECIFICATION AND RESPECTIVE SAFETY ANALYSES IN THE MATTER OF AMENDING LICENSE NO. NPF-6 ENTERGY OPERATIONS, INC.
ARKANSAS NUCLEAR ONE, UNIT TWO DOCKET NO. 50-368 t
I i
e N
i i
I e
i
?
\\.
i
Attrchm:nt 1 to l
2CAN059303 Page 2 DESCRIPTION OF PROPOSED CHANGE Table 3.7-1 of ANO-2 Technical Specifications establishes upper limits for the Lmear Power Level - High Trip Setpoint when one or more Main Steam Line Code Safety l
Valves are inoperable. The proposed change reduces the Maximum Allowable Linear Power Level-High Trip Setpoints listed in Technical Specification Table 3.7-1 and revises the associated bases. These setpoints are currently being administratively controlled to the more conservative values.
BACKGROUhD i
Specification 3/4.7.1 establishes the Limiting Conditions for Operation and Action requirements for the main steam line code safety valves. Action 3.7.1.1.a requires a reduction in the Linear Power Level-High trip setpoints when the plant is in mode 1,2, or 3 and one or more Main Steam Line Code Safety Valves are inoperable on any steam generator. The current specification refers to Table 3.7-1 which requires the Linear Power Level-High trip setpoint to be reduced to; 99.5% when one Main Steam Line Code Safety Valve is inoperable, 74.0% when two valves are inoperable, and 48.6% when three are inoperable. These values were calculated in accordance with Standard Technical Specifications (NUREG 0212) assuming a maximum steam relief capacity of 125% of steam generated at 100% power. The actual maximum steam relief capacity of the valves, l
as discussed in section 10.3 of the Safety Analysis Report, is 116.5% of the steam generated at 100% power.
l A review of the maintenance history on the main steam safety valves determined that ANO-2 had never been in a condition where the action statement (3.7.1.1.a) was invoked.
a DISCUSSION OF CHANGE The Main Steam Line Code Safety Vah es ensure that secondary system pressure will be limited to less than 110% of design pressure, during the most severe, anticipated, operational transient. The design pressure of the ANO-2 secondary system is 1100 psia.
The assumed transient comprises a turbine trip coincident with a loss of condenser heat
{
sink at 100% power. To prevent main steam pressure from exceeding 1210 psia (110% of-design pressure) under these conditions, the Main Steam Line Code Safety Valves must be l
capable of discharging all of the steam energy produced by the steam generators. Since I
the actual steam relief capacity of the valves is less than that assumed when the original i
specification was developed, an amendment is necessary to ensure that the maximum -
l allowable pressure is not exceeded. This change reduces the setpoints in Table 3.7-1 to
.i ensure that adequate relief capacity will exist under the most severe transient conditions.
j provides the calculation which was performed to determine the new 1
setpoints. This calculation is consistent with the Revised Standard Technical
)
Specifications (NUREG 1432, Revision 0) Bases for specification 3.7.1.
l i
Att: chm:nt 1 to 2CAN059303 Page 3
[
l An evaluation of the proposed change has been performed in accordance with 10CFR50.91(a)(1) regarding no significant hazards considerations using the standards m 10CFR50.92(c). A discussion of these standards as they relate to this amendment request t
follows.
Criterion 1-Does Not Involve a Significant Increase in the Probability or Consequence of an Accident Previously Evaluated.
i To prevent overpressurizing the Main Steam Header during a turbine trip coincident with a loss of condenser heat sink, the Main Steam Line Safety Valves must provide relief l
capacity equal to the steam flow from the Steam Generators. This change reduces the allowable Linear Power Level when one or more Main Steam Line Safety Valves are l
inoperable to ensure that the steam flow from the Steam Generators does not exceed the j
steam relief capacity of the remaining operable valves. With the reduced Linear Power Level-High Trip Setpoint, steam production in excess of relief capacity is precluded by actuation of the Reactor Protection System.
i i
This change further restricts operational limits on the allowed Linear Power Level when one or more main steam line code safety valves are inoperable. The proposed change does not provide any relief from the requirements of the TS. Since this change implements more conservative restrictions on plant operations, this change does not significantly l
increase the probability or consequence of any previously analyzed accident.
j i
Criterion 2 - Does Not Create the Possibility of a New or Different Kind of Accident from Any Previously Evaluated.
This change does not create any new plant configuration or operational mode. The proposed amendment does not change the design or configuration of the plant. The reduction in allowable Linear Power Level when one or more Main Steam Line Safety Valves are inoperable further restricts plant operation.
i The proposed change introduces no new modes of operation but further restricts existing plant operational modes. Since the proposed amendment does not change plant design or -
configuration and does not relax plant operational requirements, this change does not -
j create the possibility of a new or different kind of accident from any previously evaluated.
j Criterion 3 - Does Not Involve a Significant Reduction in a Margin of Safety.
This change further restricts Linear Power Level when one or more Main Steam Line
{
Safety Valves are inoperable to ensure that during the most severe anticipated operational j
transient, the Secondary System pressure will not exceed 110% of design pressure. This reduction in Maximum Allowable Linear Power Level ensure that adequate steam relief capacity will be available to prevent overpressurizing the Secondary System during the most severe anticipated operational transient.
l 1
.L Att:chment 1 to 2CAN059303 Page 4 The proposed change does not adversely affect margins of safety, since more stringent setpoints will be applied to the Reactor Trip System. Since the proposed amendment will improve the plant's capability to mitigate the consequences of accidents, this change does npqt involve a significat.. reduction in a margin of safety.
l Therefore, based on the reasoning presented above and the previous discussion of the amendment request, Entergy Operations has determined that the requested changes do not involve a significant hazards consideration.
I r
e t
+
)
l
' b I
b r
p b
I i
i 1
t f
i
(