NRC-89-0264, Application for Amend to License NPF-43,deleting Footnote on Limiting Condition of Operation 3.6.4.1 Re Opening of Suppression Chamber to Drywell Vacuum Breakers

Application for Amend to License NPF-43,deleting Footnote on Limiting Condition of Operation 3.6.4.1 Re Opening of Suppression Chamber to Drywell Vacuum Breakers

ML19332F519
Person / Time
Site:	Fermi
Issue date:	12/07/1989
From:	Sylvia B DETROIT EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML19332F520	List: ML19332F523 NRC-89-0264, Application for Amend to License NPF-43,deleting Footnote on Limiting Condition of Operation 3.6.4.1 Re Opening of Suppression Chamber to Drywell Vacuum Breakers
References
CON-NRC-89-0264, CON-NRC-89-264 NUDOCS 8912150115
Download: ML19332F519 (6)

Text

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3 i ' O. Reiph syic l Sen@ Vice prig Gent

. - K10 North Disie Hi Ed, son ~;g:=r"gtmay -  ;

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I December 7,1989 -

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NIC-89-0264

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i U. S. !belear Regulatory Ccanmission -

, Attn Document Control Desk Washington, D. C. 20555 ,

Beforences: 1) Fermi 2 NIC Docket No. 50-341 NIC License No. NPF-43 ,

2) Detroit Mison Letter to NIC, NIC-88-0283,

" Proposed Technical Specification Change (License Anerdnent) - Suppression Chanber -

Drywell Vacuum Breakers (3/4.6.4.1),"

dated Decenber 22, 1988

Subject:

Prcposed Technical Decification Change (License Anendnent) - Suppression Chanber Drvwell Vacuum Breakers (3/4.6.4.1) pursuant to 10CFR50.90, Detroit Edison Conpany hereby proposes to anend Operating License !@F-43 for the Fermi 2 plant by incorporating '

the enclosed changes into the P3 ant Technical Specifications.

Peference 2 proposed to modify the footnote asscciated with Limiting Condition of Operation (ICO) 3.6.4.1. Based on further internal review and discussions with the NIC staff we have determined that a footnote is not necessary. 'Iherefore, this submittal proposes to I delete the existing footnote on Ico 3.6,4.1. Additionally, this submittal supersedes Reference 2.

Detroit Mison has evaluated the proposed Technical Specifications against the criteria of 10CPR50.92 and determined that no significant hazards consideration is involved. The Fermi 2 Onsite Review OrganizatJon has approved and the !belear Safety Review Group has reviewed the proposed Technical Specifications and concurs with the enclosed determinations. In accordance with 10CFR50.91, Detroit Fdison has provided a copy of this letter to the State of Michigan.

8912150113 891207 ,t

PDR ADOCK 05000341 P PDC

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M-Decenbar 7,' 1989-NIC-89-0264 -

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b; If you have any' questions, please contact Mr. Glen Ohlemacher at (313) '

586-4275.  !

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. Sincerely, . -!

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. Enclosure -l f- .

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'oct A. B. Davis l E R. W. Defayette-  !

W. G. Rogers ,

J. P. Stang . j L Supervicor, Advanced Planning and Deview Section, l

[ Michigan Public Service Consnission  !

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- ?g _. ; ustac Decenber 7; 1989 0 70C-89 0264:

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s p-p, I, B. RAIPH SYLVIA, do hereby affirm that the foregoing statenents are -

E based on' facts and circunstances which are true and accurate to tlW r

.best of my knowledge'and belief.

l hk$rfrY] /h h

' B. RAIPil SYJNIA Senior Vice President

-On this day of N# l- , 1989, before me personally appeared B. Ralph Sylvia, being first duly sworn and says that he executed the foregoing as his free act and dea 3.

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't A/Ah.hMA?0 Notary Public r

ROSAUE A. ARMETTA Notcry Pubne. ha gy q MyComm!n:on ExpirosJan.11.1992 l .,

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.' Diclosure to NIC-89-0264 page 1 l IBIB3XLTION Vacuum breakers between the suppression chanber atrosphere ard drywell provide vacuum relief to the drywell after a postulated Ioss of Coolant Accident (10CA) . The condensing steam from a 14CA could cause a drywell vacuum condition to occur beyond its design value without these vacuum breakers. With the drywell in a vacuum condition, the suppression chanber-to-drywell vacuum breakers open to vent  ;

non-condensables from the suppression chanber at.nosphere to the drywell. This equalizes the pressure between the drywell ard suppression chamber. If a prinary containnent vacuum condition still exists, the Betctor Building-to-suppression chanber vacuum breakers will open to equalize the pressure between the Beactor Building and the suppression chanber. The suppression chanber-to-drywell vacuum  ;

breakers also act as chock valves during a 14CA to prevent steam flow ,

from passing through the vacuum breakers directly to the suppression

• chanber atnosphere (e.g., the valves close when drywell pressure is greater than or equal to suppression chanber air space pressure). The vacuum breakers are equipped with pneunatic actuators operatcd by pushbuttons from the main control rocan. The actuators are sized such that they have insufficient power to open the vacuum breakers if a backflow differential pressure exists.

EVAU R22 M The existing Technical Spccification 3.6.4.1 requires that all ,

suppression chanber-to-drywell vacuum breakers be closed except when '

nanually opened for inerting the containnent. The exception, "except when manually opened for inerting," is stipulated in a footnote which also requires that all vacuum breakers be closed within two (2) hours after inerting is conpleted. The bases for this footnote is to al]ow the opening of the vacuum breakers during containnent inerting to facilitate nitrogen flow from the suppression chanber atnosphere through the vent be der (s) . The nitrogen, entered from tho suppression chamber, would displace the containnent's air content through the containnent's drywell purge valves.

The proposed Technical Specification deletes the subject footnote because manually opening these vacuum breakers bypasses the pressure suppression feature of the suppression chamber. The containnent was not designcd to contain the effects of a IOCA if these vtcuum breakers are open prior to the start of a 14CA. It should be notcd that the subject vacuum breakers may nonentarily cycle open during containnent inerting because of a pressure differential. This is an operation that may occur during containnent inerting ard is consistent with the vacuum breakers design function (e.g., normally closed unless the suppression chanber air space is at a higher pressure than the drywell).

This proposed change climinates a provision from the Technical Specifications which is inappropriate and unnecessary for plant i

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Enclosure to 10C-89-0264 Page 2 operation. On this basis, Detroit D3 icon believes this change is acceptable.

E H R E H C N t U N M u it G M E M E E D G i

' In accordance with 10CFR50.92, Detroit Fdison has nede a determination that the proposed anendnent involves no significant hazards considerations. To make this determination, Detroit Fdison nust establish that operation in accordance with the proposed anendnent would not: 3) involve a significant increase in the probability or consequences of an accident previously evaluated, or 2) create the possibility of a new or different kind of accident from any accident previously evaluated, or 3) involve a significant rcduction in a nargin of safety.

1) The proposed change does not involve a significant increase in the possibility or consequences of an accident previously evaluated because the proposed change is nore conservative. The existing Technical Specification allows the suppression chanber to drywell vacuum breakers to be manually opened for inerting the containnent and does not require closure of these vacuum breakern for up to two (2) hours after inerting is conplete3. The proposed change prevents this operation by deleting the ICO's footnote. Manually opening these vacuum breakers bypasses the pressure suppression feature of the suppression chanber. 'Ihe containment was not designcd to contain the effects of a I4CA if these vacuum breakers are open prior to start of a 14CA.

2) The proposed change does not create the possibility of a new or different kind of accident from any accident previously evaluated because this change enforces a nore conservative node of operation, as described in item 1, and does not involve a physical nodification to the plant.

3) The proposed chance does not involve a significant reduction in safety because the change deletes the ICO footnote that allows manual opening of the suppression chanber to drivell vccuum breakers during inerting. This enforces a nore conservative mode of operation as described in item 1.

Based on the above, Detroit Edison has determined that the proposed anendnerc does not involve a significant hasards consideration.

R&DQf995& M ACI Detroit Fdison has reviewod the proposed Technical Epocification changes against the criteria of 10CFR51.22 for environnontal considerations. The proposed change does not involve a significant hazards consideration, nor significantly change the t3 pes or ,

significantly incroaco the anounts of effluents that ney be released  !

offsite, nor significantly increase individual or cumulative l

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1. 1helosuro to 10C-89-0264 Page 3 i

occupational radiation exposures. Based on the foregoing, Detroit BSison concludes that the proposed Technical Specifications do reet the criteria given in 10CFR51.22(c) (9) for a categorical exclusion from the requirements for an Environnental Inpact Statenent.

G REEDSI N Based on the evaluation above: 1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposa3 manner, and 2) such activities will be conducted in conpliance with the Ccanission's regulations and proposed anenonents will not be inimical to the conmon defence and security or to the health and safety of the public, i

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