ML20081F807
| ML20081F807 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 03/17/1995 |
| From: | Yelverton J ENTERGY OPERATIONS, INC. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20081F810 | List: |
| References | |
| 2CAC039503, 2CAC39503, NUDOCS 9503220276 | |
| Download: ML20081F807 (8) | |
Text
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- A 7,. $ _'.A Entergy Opermuonc,Inc.
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1448 S.R. 333 a,
. t *-. ENTERGY RecMe, AR 72801 u s0nass4888 Jerry W. Yelverton Vice Preddent Operdons ANO March 17,1995
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- U. S. Liear Regulatory Commission Document ControlDesk Mail Station PI-137 Washington, DC 20555
Subject:
Arkansas Nuclear One - Unit 2
{
Docket No. 50-368
-l License No. NPF-6 Technical Specification Change Request High Pressure Safety Injection System Throttle Valve Surveillance I
Gentlemen:
Attached for your review and approval is a proposed Technical Specification (TS) change to delete from Surveillance Requirement 4.5.2.g the verification of correct setting of electrical and/or mechanical position stops for the eight High Pressure Safety Injection (HPSI)
I Emergency Core Cooling System (ECCS) throttle valves. This change request does not affect the surveillance verification of position stops for the four Low Pressure Safety Injection (LPSI) throttle valves specified in the same surveillance requirement.
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 -
considerelions. The bases for these determinations are included in the attached submittal.
Although the circumstances of this request are neither exigent nor emergency, your prompt review and approval are requested. The modifications to ANO-2 which result in the need for the change will be completed during the upcoming 2R11 refueling outage'which is currently scheduled to begin on September 22,1995. It is requested that the license amendment be effective within thirty days ofissuance.
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9503220276 950317 lj PDR ADOCK 05000368
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U. S. NRC March 17,1995 2CANO39503 Very truly yours, 40 JWY/tfs Attachments To the best of my knowledge and belief, the statements contained in this submittal are true.
SUBSCRIBED AND SWORN TO before me, a Notary Public in and for oom County and the State of Arkansas, this 17 day of 7fl04fL
.1995. ()
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My Comniission Erpires / / - # '[M66 JUANA M.TAPP CAN PUBtc. AngAnsag JOHNSON COUNTY h = = e
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~ March 17,1995
, 2CAN039503 -
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Mr. Leonard J. Callan Regional Administrator U. S. Nuclear Regulatory Commission Region IV 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-8064 NRC Senior Resident Inspector Arkansas Nuclear One 1448 S. R. 333 Russellville, AR 72801 Mr. George Kalman NRR Project Manager Region IV/ANO-1 & 2 U. S. Nuclear Regulatory Commission NRR Mail Stop 13-H-3 One White Flint North 11555 Rockville Pike Rockville, MD 20852 Ms. Greta Dicus l
Arkansas Department of Health Division of Radiation Control and Emergency Management 4815 West Markham Street Little R ock, AR 72205 l
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i ATTACHMENT r
TD i'
2CAN039503 PROPOSED TECHNICAL SPECIFICATION AND RESPECTIVE SAFETY ANALYSES IN THE MATTER OF AMENDING LICENSE NO. NPF-6 ENTERGY OPERATIONS, INC.
ARKANSAS NUCLEAR ONE, UNIT TWO i
DOCKET NO. 50-368 i
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. Attachment to I..
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DESCRIPTION OF PROPOSED CHANGES J
. The proposed change deletes from Arkansas Nuclear One - Unit 2 (ANO-2) Technical
- Specification (TS) 4.5.2.g the requirement to verify the correct setting of the electrical and/or mechanical position stops for all eight High Pressure Safety Injection (HPSI) Emergency Core Cooling System (ECCS) throttle valves.
The proposed change does not affect.the requirement to perform this verification for the Low Pressure Safety Injection (LPSI) ECCS throttle valves which is also specified in the same surveillance requirement.
BACKGROUND ~
r' The'HPSI ECCS throttle valves are normally closed, motor-operated valves (MOVs) that.
have a safety function to open in order to allow flow of safety injection water into the reactor i
coolant system (RCS). As originally configured, the valves have electrical position stops (limit switches) which are set to obtain the required flow distribution for HPSI following a loss of coolant accident (LOCA). Due to the possibility of a change in the setting of the position stops from various causes, TS 4.5.2.g requires that they be verified at least once each eighteen months.
l DISCUSSION OF CHANGE l
During refueling outage 2R10 which was completed in April 1994, a modification identified as l
Design Change Package (DCP) 93-2012 was installed. This DCP included the addition of l
manual valves upstream of four of the eight MOVs to provide the flow throttling function previously accomplished by the MOVs. A similar modification will be installed in the other four HPSI injection lines during refueling outage 2R11 (currently scheduled to begin on September 22,1995). Following completion of this modification, verification of the correct position stop settings for the HPSI MOVs will not be necessary since the valves will then actuate to the fully open position. Actuation to the fully open position will be verified as part of the ASME Section XI testing program. HPSI flow will be controlled by manual valves that will be fixed in position by tack welding a valve handle restraint to the valve yoke following satisfactory verification of flow balancing. Flow balancing assures adequate flow to the Reactor Coolant System in the event of a LOCA. The modified configuration is similar to the existing configuration of ANO Unit 1.
NUREG-1432, restructured " Standard Technical Specifications - Combustion Engineering Plants," contains surveillance requirement (SR) 3.5.2.9 which is equivalent to ANO-2 TS 4.5.2.g. It is marked as a specification requiring plant specific input. The basis for SR 3.5.2.9 i
states, "This SR is not required for units with flow limiting orifices." Since manual throttle l
valves fixed into position function as flow limiting orifices, the proposed change is consistent with the corresponding requirement in NUREG-1432.
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Attachment to
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2CAN039503 DETERMINATION OF NO SIGNIFICANT HAZARDS CONSIDERATION i
An evaluation of the proposed change has been performed in accordance with 10CFR50.91(a)(1) regarding no significant hazards considerations using the standards in t
10CFR50.92(c). A discussion of these standards as they relate to this amendment request follows:
Criterion 1 - Does. Not Involve a Significant Increase in the Probability or Consequences of an Accident Previously Evaluated.
The HPSI system is not an initiator of a previously evaluated accident; therefore, the 1
probability of a previously evaluated accident will not be increased by the proposed change.
Accidents which require the use of HPSI will not have any increased consequences since the new injection / isolation valve arrangement is at least as reliable as the previous valve arrangement. No part of the proposed change has any adverse effect upon the HPSI system response or function. The new manual valves will perform the throttling function previously performed by the HPSI isolation MOVs without reliance upon any electrical equipment (MOV limit switches). The proposed change does not affect routing of HPSI piping or affect total flow characteristics of the system. The proposed change to remove the requirement to verify the correct settings of position stops for the HPSI throttle valves is consistent with 'NUREG-1432, restructured " Standard Technical Specifications - Combustion Engineering Plants,"
since the manual throttle valves fixed into position serve the function of, and are equivalent to, flow limiting orifices.
Therefore, this change does act involve a significant increase in the probability or consequences of any accident previously evaluated.
Criterion 2-Does Not Create the Possibility of a New or Different Kind of Accident from any Previously Evaluated.
The proposed change does not change the function or mode of operation of the HPSI system.
The failure of the new MOVs to function will have no different effect than failure of the previously installed MOVs and such failure is enveloped by assumptions in the existing safety analysis, i.e., redundant trains will still be able to function. The new manual valves are less likely to fail in operation since they are fixed into position by tack-welded locking devices and therefore perform their function passively. Inadvertent manipulation of the manual valves will be prevented by the locking arrangement. There are no new functions or modes being accomplished by the MOVs. The throttling function to be performed by the manual valves will be more reliably performed by passive components than by active electrical circuits. The change eliminates uncertainty in throttle valve position as a result oflimit switch tolerances and repeatability which form the basis for the current surveillance requirement for periodic verification.
' Attachment to
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2CAN039503 Therefore, this change does not create the possibility of a new or different kind of accident from any previously evaluated.
I Criterion 3 - Does Not Involve a Significant Reduction in the Margin of Safety.
No margin of safety will be reduced or affected by the proposed deletion of the surveillance requirement. The new manual valves will be throttled to produce a system flow balance equivalent to the current one, and the balance will continue to be confirmed by surveillance,
testing in accordance with TS requirements.
Therefore, this change does Dat involve a significant reduction in the margin of safety.
The Commission has provided Guidance in 51 FR 7750 dated March 6,1986, concerning the i
application of these 10CFR50.92 standards by providing examples of amendments which are likely to involve Da significant hazards considerations. The proposed amendment most closely matches example B(ix): "A repair or replacement of a major component or system important to safety, if the following conditions are met: (1) The repair or replacement process involves practices which have been successfully implemented at least once on similar components or systems elsewhere in the nuclear industry or in other industries, and does not involve a significant increase in the probability or consequences of an accident previously evaluated or create the possibility of a new or different kind of accident from any accident previously evaluated; and (2) The repair or replacement component or system does not result in a significant change in its safety function or a significant reduction in any safety limit (or limiting condition of operation) associated with the component or system."
Therefore, based upon the reasoning presented above and the previous discussion of the amendment request, Entergy Operations has determined that the requested change does Dat involve a significant hazards consideration.
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PROPOSED TECHNICAL SPECIFICATION CHANGES