ML20034E140
| ML20034E140 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 02/12/1993 |
| From: | NIAGARA MOHAWK POWER CORP. |
| To: | |
| Shared Package | |
| ML20034E135 | List: |
| References | |
| NUDOCS 9302250159 | |
| Download: ML20034E140 (7) | |
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ATTACHMENT A L
NIAGARA MOHAWK POWER CORPORATION 1 -L UCENSE NO. NPF-69 i
DOCKET 50410 i
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PROPOSED CHANGES TO THE TECHNICAL SPECIRCATION -
Replace exisung pages 1-11 and 3/4 9-1 with the attached mised pages. 'Ihese pages base been i
retyped in their entirety with marginal marking to indicate changes to the text.
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-9302250159 930212
.PDR ADOCK 05000410 P
PDR-002951LL Page 1 of1 i
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'I IABLE 1.2 OPERATIONAL CONDITIONS AVERAGE REACTOR CONDITION MODE SWITCH POSITION COOLANT TEMPERATURE 1.
Power Operation Run Any temperature 2.
Startup Startup/ Hot Standby Any temperature i
3.
Hot Shutdown Shutdown *,' '
> 2OO
- F j
4.
Cold Shutdown Shutdown *,*
- t s200'F 5.
Refuelingt t Shutdown or Refuel * #
5140 F l
l TABLE NOTATIONS The reactor mode switch may be placed in the Run or Startup/ Hot Standby position to test the switch interlock functions provided that the control rods are verified to remain i
fully inserted by a second licensed operator or other technically qualified member. of the unit technical staff.
The reactor mode switch may be placed in the Refuel position while a single control rod is being moved provided that the one-rod-out interlock is OPERABLE, l
t The reactor mode switch may be placed in the Refuel position while a single control rod drive is being removed from the reactor pressure vessel per Specification 3.9.10.1 tt Fuel in the reactor vessel with the vessel head closure botts less than fully tensioned or j
with the head removed.
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- See Special Test Exceptions 3.10.1 and 3.10.3.
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NINE MILE POINT - UNIT 2 1-11 Amendment No.
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. 3/4.9 REFUELING OPERATIONS 3/4.9.* REACTOR MODE SWITCH '
LIMITING CONDITIONS FOR OPERATION 3.9.1 The reactor mode switch shall be OPERABLE and locked in the Shutdown or Refuel position. When the reactor mode switch is locked in the Refuel position:
a.
A control rod shall not be withdrawn unless the Refuel position one-rod-out interlock is OPERABLE.
b.
CORE ALTERATIONS shall not be performed using equipment associated with a Refuel position interlock unless at least the following associated Refuel position interlocks are OPERABLE for such equipment.
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All rods in.
2.
Refuel platform position.
3.
Refuel platform hoists fuel-loaded.
4.
Fuel grapple position.
5.
Service platform hoist fuel-loaded.
APPLICABILITY: OPERATIONAL CONDITION 5' #, OPERATIONAL CONDITIONS 3 and 4 when the reactor mode switch is in the Refuel position.
ACTION:
i a.
With the reactor mode switch not locked in the Shutdown or Refuel position as specified, suspend CORE ALTERATIONS and lock the reactor. mode switch in the Shutdown or Refuel position.
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b.
With the one-rod-out interlock inoperable, lock the reactor mode switch in the Shutdown position.
c.
With any of the above required Refuel position equipment interlocks inoperable, suspend CORE ALTERATIONS with equipment associated with the inoperable Refuel position i
equipment interlock.
See Special Test Exceptions 3.10.1 and 3.10.3.
- The reactor shall be maintained in OPERATIONAL CONDITION 5 whenever fuelis in the reactor vessel with the vessel head closure bolts less than fully tensioned or with the head -
j removed.
j NINE MILE POINT - UNIT 2 3/4 9-1 Amendment No.
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ATTACIIMENT B j
NIAGARA MOllAWK POWER CORPORATION LICENSE NO. NPF-69 i
DOCKET NO. 50 410 l
i SUPPORTING INFORMATION AND NO SIGNIMCANT HAZARDS l
CONSIDERATIONS ANAIXSIS i
1 Background
l Technical Specification Table 1.2 defines the reactor mode switch positions and average coolant temperatures for the five Operational Conditions at Nine Mile Point Unit 2. The "**" footnote to
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Table 1.2 is applicable only to Operational Conditions 3 and 4. In the existmg specifications, this '
footnote permits the reactor mode switch to be placed in the refuel position with the plant shutdown and the reactor head tensioned while a single rod is being recoupled, provided the one-rod-out interlock is OPERABLE. In addition, the "t" footnote to Table 1.2 allows for a single control rod drive to be removed while in Cold Shutdown in accordance with the provisions of Specification 3.9.10.1. 'Ihese provisions allow a control roci.o be uncoupled from its drive for drive replacement or maintenance without the reactor head being removed. However, the provisions do not permit i
venting of or scram time testing of mntrol rods in Operational Condition 3 or 4.
Discussion j
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'Ihe one-mdeut interlock associated with the refuel position of the reactor mode switch provides i
protection agamst prompt reactivity excursions. This one-mdeut restriction ~is enforced by a' redundant logic circuit that uses the all-rods-in signal and a rod selection signal to prevent the j
selection of a second control rod for movement when any other contml rod is not fully inserted.
l Operability of the one-rodeut interlock is required by Specification 3.9.1 for OPERATIONAL CONDITION 5 and for Special Test Exceptions allowed 1,y Specifications 3.10.1 and 3.10.3.
Since the mode switch in the Shutdown position blocks rod movement, the movement of the switch to Refuel (or to Startup or Run) is recmsmy to move a rod for recoupling (e.g., after repairs on the j
. mntml rod drive) or other maintenance and testing activities. Rod movement in the Refuel position i
is limited to one rod by the redundant logic of the one-rodcut interlock.
l Technical Specification 3.1.1 requires SHUTDOWN MARGIN to be maintained in OPERATIONAL i
CONDITIONS 1, 2, 3, 4, and 5. SHUTDOWN MARGIN is the amount of reactivity by which the reactor would be suberitical assuming all wntrol rods are fully inserted except for the single control l
rod having the highest reactivity wonh which is assumed fully withdrawn. 'Ihe one-mdeut interlock, together with the requirements for adequate SHUTDOWN MARGIN during refueling, provides protection against pmmpt reactivity excursions by preventing withdrawal of more than one l
control rod and by ensuring the core remains suberitical with any one control rod withdrawn.
1 Technical Specification Table 1.2 currently allows very limited conditions under which a control rod may be withdrawn in OPERATIONAL CONDITIONS 3 and 4. Consequently, post-maintenance i
and surveillance testing on contml rod drives is a critical path activity during plant startup after a refueling outage. This change would permit the performance of control rod drive testing during cold shutdown, thereby shortening the critical path schedule. While the poposed change will increase the i
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. fn:quency of single control rod withdrawals in OPERATIONAL CONDmONS 3 and 4 by expand-ing the allowance contained in the """ footnote to include the performance of testing and maintenance activities (e.g., rod exercises), it will not incmase the pmbability of withdrawal events since the withdrawals would have been performed under existing Technical Specifications in l
OPERATIONAL CONDmONS 1, 2, or 5. Testing and maintenance are curmndy allowed (in all i
BWRs) in OPERATIONAL CONDmONS I and 2 where they are not under the control of the one-md-out interlock.
1 To ensure that the one-rod-out interlock is operable when required, the APPLICABILITY for l
Specification 3/4.9.1 is also revised to include OPERATIONAL CONDmONS 3 or 4 with die i
reactor mode switch in the Refuel position. This revision expands the applicability of the appmpriate testing mquirements for the one-rod-out interlock to Operational Conditions 3 and 4.
The proposed change to Technical Specification Table 1.2 is similar to existing appmved Technical l
Specification Table 1.2 specifications in other BWRs (la Salle, Clinton, Peny, and River Bend).
Grand Gulf received a similar amendment to their Technical Specifications on Septemixx 15, 1989.
Based on the above analysis, there is reasonable assurance that operation of Nine Mile Point Unit 2, in the proposed manner, will not endanger the public health and safety and that issuance of the pmposed amendment will not be inimical to the common defense and security.
I Conclusion r
The SHUTDOWN MARGIN required by Specification 3/4.1.1 ensures the reactor will be maintained subcritical even with the highest worth rod fully withdrawn. ' Die one-rod-out interlock is
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automatically imposed whenever the reactor mode switch is placed in the refuel position. By
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expanding the applicability of Specification 3/4.9.1, the revision will impose surveillance requirements to ensure the one-mdeut interlock is OPERABLE prior to allowing withdrawal of a contml rod in OPERATIONAL CONDITIONS 3 and 4. The provisions assure that the reactor will remain suberitical during single rod movement with the mode switch in the refuel position. Rese revisions 1
are in accordance with pmvious staff approvals and existing Technical Specifications in other BWR reactors, provide needed flexibility for maintenance and testing of rods, are not significandy different j
from the cunent permitted operations of rod withdrawal and do not increase the probability of a md withdrawal event.
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10CFR50.91 requires that at the time a licensee requests an amendment, it must provide to the l
commission its analysis, using the standards in 10CFR50.92, conceming the issue of no significant hazards consideration. Therefore, in accordance with 10CFR50.91, the following analysis has been performed:
ne oneration of Nine Mile Point Unit 2. in accordance with the proLxml amendment. will not imohe n significant inen ase in the probability or consecuences of nn necident pnviously evaluated, i
This revision would allow a single control rod to be withdrawn under control of the reactor mode j
switch refuel position one-rod-out interlock in OPERATIONAL CONDmONS 3 and 4. His i
interlock is explicitly assumed in the safety analysis for contml rod removal error during refueling.
l A prompt reactivity excursion could potentially result in fuel failure. He one-rod-out interlock, together with the mquirements for adequate SHUTDOWN MARGIN dming refueling, provides pmtection against prompt reactivity excursions by preventing withdrawal of more than one control j
rod and ensuring the core remains subcritical with any one control rod withdrawn. The addition of i
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. surveillance requimments for the one-md-out interlock will assure the interlock is operable prior to withdmwal of a mntml rod in OPERATIONAL CONDmONS 3 and 4. Although tids change would allow an increase in the frequency of single contml rod withdrawals in OPERATIONAL CONDmONS 3 and 4, the probability of previously analyzed accidents, including control md withdrawal error, is not affected.
l The consequenas of previously analyzed acx:idents in OPERATIONAL CONDmONS 3 and 4 are not affected by this pmposed change. 'Ihe SHUTDOWN hMRGIN requirements of Specification 3.1.1 require the reactor to be subcritical when all contml rods are fully inserted exxpt for the single control rod having the highest reactivity worth being fully withdrawn. The one-roduit interlock of the reactor mode switch refuel position pennits only a single contml rod to be withdrawn. The proposed change will not result in the reactor hasing the potential for attaining criticality in t
OPERATIONAL CONDmONS 3 and 4 or affect the initial conditions assumed in any design basis acrident analysis.
Based on the above, the probability and consequenas of pmviously analyzed accidmts are not
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increased.
The operation of Nine Mile Point Unit 2. In accorxlance with the omooed amendment. will not cmate the oossibility of a new or differrnt kind of accident from any accident orrviously evaluated.
Single control rods can be withdrawn in OPERATIONAL CONDmONS 3 and 4 under the enstmg Technical Specifications to permit contml rod rcroupling. 'Ihe proposed change wotdd merely expand this pmvision to other mntrol rod maintenance and testing actisities performed in OPERATIONAL CONDmONS 3 and 4. The withdrawal ofindisidual control rods in OPERATIONAL CONDmONS 3 and 4 is a mode of operation permitted under limited circumstances by the existing Technical Specifications. The mvision to Specification 3/4.9.1 pmvides additional assuranx that the one-rod-out interlock is OPERABLE in OPERATIONAL i
CONDmONS 3 and 4.
The additional mntml rod maintenance and testing actisities which could be performed in OPERATIONAL CONDmONS 3 and 4 are permitted by the existing Technical Specifications in OPERATIONAL CONDmONS 1,2 and 5. Examples of activities which could be performed include venting of control rods following a mactor scram or contml rod drive system outage, normal contml rod insertion / withdrawal timing and adjustment, control rod scram time testing and mntml rod friction testing.
Sinx single contml rod withdrawal for the purpose of recoupling is currently allowed in i
OPERATIONAL CONDmONS 3 and 4, and Specification 3/4.9.1 is resised to ensure the one-rod-out interlock is OPERABLE, this change does not create the possibility of a new or different kind of axident from any presiously evaluated.
The operation of Nine Mile Point Unit 2. in accordance with the oronosed amendment. will not involve a sienificant reduction in a marcin of safety.
I The Technical Specifications currently permit single mntrol rod withdrawal for the purpose of control rod recoupling when in OPERATIONAL CONDmONS 3 or 4 if the one-rod-out interlock is OPERABLE. 'Ihis change merely allows additional activities for which a single control rod may be 002951LL Page 3 of 4
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. withd'rawn when in OPERATIONAL CONDmON 3 or 4, with the same restriction that the one-l rodcut interlock be OPERABLE.
While the Technical Specificabons currently allow limited control rod withdrawal in OPERATIONAL CONDmONS 3 and 4 provided the one-rodeut interlock is OPERABLE, they have no surveillance requirements for the one' rod-out interlock while in OPERATIONAL CONDmON 3 or 4. 'Ihe revision to the APPUCABIUTY staterrent in Specification 3/4.9.1 invokes the Surveillance Requirements for the one-rodcut interlock whenever control rod withdrawal is performed in OPERATIONAL CONDmONS 3 and 4. Together, the operability requirements for the one-rod-out interlock and the SHUTDOWN MARGIN requirerrents of Specification 3.1.1 ensure tie reactor will be maintained subcritical during single control rod withdraw 21s. "Iherefore, this change will not invohe a significant reduction in the margin of safety.
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