Text

Proposed Tech Specs,Clarifying Applicability of Containment Oxygen Concentration
	ML17199U844
Person / Time
Site:	Dresden
Issue date:	03/18/1988
From:	; COMMONWEALTH EDISON CO.
To:	;
References
	NUDOCS 8803300257
	Download: ML17199U844 (16)
	v • d • e

3.7 LIMITING CONDITION FOR OPERATION (Cont'd.)

c.

Reactor operation may continue for fifteen (15) days provided that at least one position alarm circuit for each operable vacuum breaker is operable and each suppression chamber -

drywell vacuum breaker is physically verified to be closed immedi-ately and daily thereafter.

5.

Oxygen Concentration

a.

When the reactor is in the RUN mode, the primary containment atmosphere concentra-tion shall be less than 4 percent by volume.

3/4.7-14 2097b 8863:30

.. Q257.*":38.(1:318 :.*11 PDR "ADOCK*05000237

j P

... DCD*

1 I DRESDEN II DPR-19 Amendment No. 'JA* ~* ~

4.7 SURVEILLANCE REQUIREMENTS (Cont'd.)

demonstrate that with initial differential pressure of not less than 1.0 psi, the differ-ential pressure decay rate does not exceed the rate which would occur through a 1-inch orifice without the addition of air or nitrogen.

5.

Oxygen Concentration The oxygen concentration in the primary contain-ment shall be verified to be within the limit of specification 3.7.A.5.a.

at least once per seven days, while in the RUN Mode.

3.7 LIMITING CONDITION FOR OPERATION 2097b ccont'd.)

b.

When the oxygen concen-tration in the primary containment exceeds the limit given in specification 3.7.A.S.a. above, within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months restore the oxygen concentration to within the limit, or within the next 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months be in at least the STARTUP/

HOT STANDBY Mode.

6.

Containment Atmospheric Dilution and Purge

a.

Whenever the reactor is in power operation the normal containment makeup inerting system shall be operable and capable of supplying nitrogen to containment for atmosphere dilution if required by post LOCA conditions.

If this specification cannot be met, the system must be restored to an operable condition within 7 days or 3/4.7-15 DRESDEN II DPR-19 Amendment No. }4, ~. f.¢ 4.7 SURVEILLANCE REQUIREMENTS (Cont'd.)

6.

Containment Atmospheric Dilution and Purge

a.

Once a month, the valves in the nitrogen makeup system shall be actuated to determine operability.

3.7 LIMITING CONDITION FOR OPERATION (Cont'd.)

2097b

d.

Whenever the reactor is in power operation, the pdmary containment oxygen sampling system shall be operable.

If this specification cannot be met, the system must be restored to an operable condition within 7 days or the reactor must be taken out of power operation.

e.

The maximum containment repressurization pressure using the conta.inment makeup inerting system shall be 26 p~ig.

7.

Drywell Suppression Chamber Differential Pressure

a.

When the reactor is in the RUN Mode, the dif-ferential pressure between the drywell and suppression chamber shall be maintained at equal to or greater than 1.00 psid.

3/4.7-17 DRESDEN II DPR-19 Amendment No.. ¥, ~

4.7 SURVEILLANCE REQUIREMENTS (Cont'd.)

d.

The containment oxygen analyzing system shall be functionally teste.d once per week and shall be calibrated once per 6 months.

7.

Drywell Suppression Chamber Differential Pressure

a.

The pressure dif ferentlal between the drywell and suppression chamber shall be recorded at least once each shift when in the RUN mode.

3.7 LIMITING CONDITION FOR OPERATION (Cont'd.)

I l

I

b.

When the differential pressure is less than the limit given in specification

c.

d.

3. 7. A. 7. a. above,.*

except as -specified -

in 3.7.A.7.c and.d below, wi~hin 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months rest~re the. *..

differential pressure to within the limit, or within the next 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months be in at.--least

the STARTUP/HOT STANDBY Mode. and fo*-.

COLD_. SHUTDOWN within the following 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

This pressure differential may be decreased to less than 1.00 psid for a maximum of 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months during required operability testing of the drywe 11 pressure suppression chamber vacuum breakers, HPCI testing and reactor pressure relief valve testing.

If the Specifications of 3.7.A.7.c cannot be met, and the differential pressure cannot be restored within the subsequent six (6) hour period, an orderly shutdown 3/4.7-18 DRESDEN II DPR-19 Amendment No. 7f, )J1.

4.7 SURVEILLANCE REQUIREMENTS (Cont'd.)

3.7 2097b DRESDEN II DPR-19 Amendment No. 1t4, ~, ~

LIMITING CONDITION FOR OPERATION BASES (Cont'd.)

Reactor operation is permissible if the bypass area between the primary containment drywell and suppression chamber does not exceed an allowable area.

The allowable bypass area is based upon analysis considering primary system break area, suppression chamber effective-ness, and containment design pressure.

Analyses show that the maximum allowable bypass area is equivalent to all vacuum breakers open the equivalent of 1/16" at all points along the seal surface of the disk (see Dresden Special Report No. 23).

Each drywell-suppression chamber vacuum breaker is fitted with a redundant pair of position switches which provide signals of disk position to panel mounted indicators and annunciate an alarm in the control room if the disk is open more than allowable.

The alat"m systems meet the intent of IEEE 279 standards. *The quality of the alarm system just~f ies continued t"eactor opet"ation for 15 days between differential pressure decay t"ate tests if one alarm system is inoperable for one or more operable vacuum breakers.

The relatively small containment volume inherent in the GE-BWR pressut"e suppt"ession containment and the large amount of zirconium in the cot"e are such that the occurrence of a very limited (a percent or so) reaction of the zit"conium and steam dut"ing a loss of coolant accident would lead to the liberation of sufficient hydrogen to a result in a flammable concentration in the containment.

Subsequent ignition of the hydrogen if it is present in sufficient quantities to result in excessively rapid recombination, could lead to failut"e of the containment to maintain a low leakage integrity.

The 43 oxygen concentration m1n1m1zes the possibility of hydrogen combustion following a loss of coolant accident.

The occurrence of primary system leakage following a major' refueling outage or other scheduled shutdown is much more probable than the occurrence of the loss of coolant accident upon which the specified oxygen concentration limit is based.

Permitting access to the drywell for leak inspections during a startup is judged prudent in terms of the added plant safety offered without significantly reducing the margin of safety.

Thus, to pr'eclude the possibility of starting the reactor and operating for extended periods of time with significant leaks in the primary system, leak inspections are scheduled during startup per'iods, when the primary system is at Or" near rated operating temperature and pressure.

A 24-hour t"elaxation of the oxygen requirement period is judged to be sufficient to perform the leak inspection and establish the required oxygen concentration.

The 24-hour time limit also provides a restricted time period for* a containment entry to be made with the reactor at power in order to affect minor repairs to safety equipment and equipment lubrication.

B 3/4.7-36

3.7 LIMITING CONDITION FOR OPERATION (Cont'd.)

2098b

c. *Reactor operation may continue for fifteen (15) days provided that at least one position alarm circuit for each operable vacuum breaker is operable and each suppression chamber

- drywell vacuum breaker is physically verified to be closed inunediately and daily thereafter.

5.

Oxygen Concentration

a.

When the reactor is in the RUN mode, the primary containment atmosphere oxygen concentration shall be less than 43 by volume.

3/4.7-14 DRESDEN III DPR-25 Amendment No. 0, ~, "/A 4.7 SURVEILLANCE REQUIREMENTS (Cont'd.)

demonstrate that with initial differential pressure of not less than 1.0 psi, the differential pressure decay rate does not exceed the rate which would occur through a 1-inch orifice without the addition of air o.r nitrogen.

5.

Oxygen Concentration The oxygen concentration in the primary contain-ment shall be verified to be within the limit of Specification 3.7.A.5.a. at least once per*seven days, while in the RUN mode.

'(;.

3.7 I-2098b LIMITING CONDITION FOR OPERATION (Cont'd.)

b.

When the oxygen concentration in the primary

~ontainment exceeds the limit given in Specification 3.7.A.5.a. above, within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months restore the oxygen concentration to within the limit, or within the next 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months be in at least the STARTUP/HOT STANDBY mode.

6.

Containment Atmospheric Dilution and Purge

a.

Whenever the reactor is in power operation the normal containment makeup inerting system shall be operable and capable of supplying nitrogen to containment for atmosphere dilution if required by post LOCA conditions.

If this specification cannot be met, the system must be restored to an operable condition within 7 days or 3/4.7-15 DRESDEN III DPR-25 Arnendmen t No. l,A, ~, pi:,

4.7.SURVEILLANCE REQUIREMENTS (Cont'd.)

6.

Containment Atmospheric Dilution and Purge

a.

Once a month, the valves in the nitrogen makeup system shall be actuated to determine

operability.

I*

-~

3.7 LIMITING CONDITION FOR OPERATION (Cont'd.)

d.

Whenever the reactor is in power operation, the primary containment oxygen sampling system shall be operable.

If this specification cannot be met, the system must be restored to an operable condition within 7 days or the reactor must be taken out of power operation.

e.

The maximum containment repressurization pressure using the containment makeup inerting system shall be 26 psig.

7.

Drywell Suppression Chamber Differential Pressure

a.

When the reactor is in the RUN mode, the differential pressure between the drywell and suppression chamber shall be maintained at equal to or greater than 1.00 psid.

3/4.7-17 2098b DRESDEN III Amendment No.

4.7 SURVEILLANCE REQUIREMENTS (Cont'd.)

d.

The contairunent oxygen analyzing system shall be functionally tested once per week and shall be calibrated once per 6 months.

7.

Drywell Suppression Chamber Differential Pressut'e

a.

The pt'essut'e dif fet'ential between the drywell and suppt'ession chamber shall be recorded at least once each shift when in the RUN mode.

3.7 LIMITING CONDITION FOR OPERATION (Cont'd.)

b.

When the differential pressure is less than the limit given in Specification.

3.7.A.7."a. above, except as specified in 3.7.A.7.c and.d below, within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months restore the differential pressure to within:

the limit or within the next 6 hour~. b.e..

in at least the STARTUP/HOT STANDBY,

1Mode.. and in'1 COLD

~HUTOoWN wfthin the following 24 hout's.

c.

This pressure di~f¢'te_ntial may ;be decreased t_o.. le~s,

than 1.00 psid for

.a maximum of 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months during required operability testing of the drywell pressure suppression chamber vacuum breakers, HPCI testing and reactor pressure re lief valve testing.

d.

If the Specifications of 3.7.A.7.c cannot be met, and the differential pressure cannot be restored within the subsequent six (6) hour period, an orderly shutdown 3/4.7-18 DRESDEN III DPR-25 Amendment No.~. 75 4.7 SURVEILLANCE REQUIREMENTS cc.ont Id.)

3.7 2098b DRESDEN III Amendment No.

LIMITING CONDITION FOR OPERATION BASES (Cont'd.)

. DPR-25

~. ¥3. ts Reactor operation is permissible if the bypass area between the primary containment drywell and suppression chamber does not exceed an allowable area.

The allowable bypass area is based upon analysis considering primary system break area, suppression chamber effectiveness, and conlainment design pressure.

Analyses show that the maximum allowable bypass area is equivalent to all vacuum breakers open the equivalent of 1/16" at all points along the seal surface of the disk (see Dresden Special Report No. 23).

. Each drywell-suppression chamber vacuum breaker is fitted with a redundant pair of position switches which provide signals of disk position to panel mounted indicators and annunciate an alarm in the control room if the disk is open more than allowable.

The alarm systems meet the intent of IEEE 279 standards.

The quality of the alarm system justifies continued reactor operation for 15 days between differential pressure decay rate tests if one alann system is inoperable for one or more operable vacuum breakers.

The relatively small containment volume inherent in the GE-BWR pressure suppression containment and the large amount of zirconium in the core are s~ch that th~ occurrence of a very limited (a percent or so) reaction of the zirco.nium and steam during a loss of coolant accident would lead to the liberation of sufficient hydrogen to a result in a flammable concentration in the containment.

Subsequent ignition of the hydrogen if it is present in sufficient quantities to result in excessively rapid recombination, could lead to failure of the containment to maintain a low leakage integrity.

The 43 oxygen concentration minimizes the possibility of hydrogen combustion following a loss of coolant accident.

The occurrence of primary system leakage following a major refueling outage or other scheduled shutdown is much more probable than the occurrence of the loss of coolant accident upon which the specified oxygen concentration limit is based.

Permitting access to the drywell for leak inspections during a startup is judged prudent in terms of the added plant safety offered without significantly reducing the margin of safety.

Thus, to preclude the possibility of starting the reactor and operating for extended periods of time with significant leaks in the primary system, leak inspections are scheduled during startup periods, when the primary system is at or near rated operating temperature and pressure.

A 24-hour relaxation

period of the oxygen requirement is judged to be sufficient to perfonn the leak inspection and establish the required oxygen concentration.

The 24-hour time limit also provides a restricted time period for a containment entry to be made with the reactor at power in order to affect minor repairs to safety equipment and equipment lubrication.

B 3/4.7-36

ATTACHMENT 2

SUMMARY

OF CHANGES A total of twenty-four (24) changes to the Dresden station Units 2 and 3 Technical Specifications have been identified (12 per unit) and are listed below as follows:

1)

Page 3/4.7-14, DPR-19 and 25 (a)

Limiting condition for Operation (LCO), Technical Specification 3.7.A.5.a - Delete Item (a) and replace with following statement, "When the reactor is in the RUN Mode, the primary containment atmosphere concentration shall be less than 4 percent by volume."

(b) surveillance Requirements Technical Specification 4.7.A.5 - Delete Item 5, entitled "Oxygen Concentration" and replace with following statement, "The oxygen concentration in the primary containment shall be verified to be within the limit of Specification 3.7.A.5.a at least once per seven days, while in the RUN Mode."

2)

Page 3/4.7-15, DPR-19 and 25 (a)

LCO - Technical Specification 3.7.A.5.b - Delete Item (b) and replace with following statement, "When the oxygen concentration in the primary containment exceeds the limiting given in... be in at least the STARTUP/HOT STANDBY Mode."

3)

Page 3/4.7-17, DPR-19 and 25 (a)

LCO - Technical Specification 3.7.A.7.a - Delete Item (a.l) and replace with following statement, "When the reactor is in the RUN Mode, the differential pressure... or greater than 1.00 psid."

(b) surveillance Requirement 4.7.A.7.a - Delete phrase "When the differential pressure is required.", and replace with phrase "When in the RUN Mode.", so the Surveillance Requirement now reads, "The pressure differential between.... when in. the RUN Mode."

., 4)

Page 3/4.7-18, DPR-19 and 25 - Limiting Condition of Operation (a)

Insert new item, Technical Specification 3.7.A.7.b, which reads as follows:

'!When the differential pressure is less than the limit given in Specification 3.7.A.7.a above... in at least the STARTUP/HOT SHUTDOWN Mode and in the COLD SHUTDOWN within the following 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months ."

(b)

Relabel Technical Specification Item 3.7.A.7.a.(2), to be Item 3.7.A.7.c.

(c)

In existing Technical Specification 3. 7.A. 7.a. (2) (now relabeled to be 3.7.A.7.c) insert the word pressure preceeding the word differential so the statement now reads "This pressure differential may be..* "

(d)

Relabel Technical Specification Item 3.7.A.7.b, to be Item 3.7.A.7.d.

(e)

In existing Technical Specifica~ion 3.7.A.7.b (now relabeled to be 3.7.A.7.d), change "3.7 *. A.7.a:* to "3;*.1.A.7.c" to reflect change 4(d).

5)

Page 83/4.7-36, DPR-19 and 25 (a)

Fourth paragraph, fourth line - Delete The 24.,...hour period to provide inerting" and replace with "A 24-hour relaxation of the oxygen requirement.. period", so the sentence. now re.ads "A 24-hour relaxation **. the* required oxygen *concentration~" *

(b)

Add new sentence to bottom of fourth paragraph that reads "The 24-hour time limit also provides a restricted time period for a containment entry to be made with the reactor at power in order to affect minor repairs to safety equipment and equipment lubrication."

4383K

ATTACHMENT J DESCRIPTION OF PROPOSED AMENDMENT REQUEST An item by item* description of the proposed changes requested as part of this amendment is provided for information and use. can be referred t? in order to reference back to a given change and.its affected page.

overall, the changes that are*described in this proposed amendment are a result of providing a clear action statement should the oxygen concen-tration or torus drywell differential pressure LCO's be exceeded.

The action statement would provide 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months to either restore the LCO or be in STARTUP/HOT STANDBY in the subsequent 6. hours and_COLD SHUTDOWN in the following 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

There are several administrative changes associated with this amendment where the affected oxygen concentration or torus drywell differential pressure Technical Specifications have been renUmbered as a result of.this change.

Finally, several changes have been made to the Technical Specification and/or Bases for clarification. These changes, as well as the numbering changes, are considered to be administrative in nature.

Item l(a)

This proposed change changes the applicability of the LCO from power operation to the RUN Mode.

Additionally, the change clarifies the oxygen concentration to be 4\\ by volume.

Item l(b)

This proposed change clarifies the applicability of the oxygen concentra-tion surveillance to the time period when the Leo is applicable, i.e.,

when in the RUN Mode.

Item 2(a)

The proposed change eliminates references subsequent to going to the RUN Mode and prior to a shutdown. It also establishes a 24-hour clock to restore the Leo or be in at least STARTU~/HOT STANDBY in the following 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months .

i Item 3(a)

This proposed change eliminates the refe~erices.to timeclocks subsequent to going to RUN and prior to a shutd.own.

Additibnally, it rewords the appli-cability of this Leo to the RUN Mode*.

--=----~_.:::- -.--==..:::: =:. - --

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Item 3(b)

ATT. 3 2.,-*

This proposed change clarifies the applicability of the surveillance requirement to when in the RUN Mode in lieu of when differential pressure is required.

Item 4(a)

This proposed change creates a new paragraph in Technical Specification 3.7.A.7.b.

The paragraph establishes a 24-hour timeclock to restore the LCO or at least be in STARTUP/HOT STANDBY in the subsequent 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and COLD SHUTDOWN in the following 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

Item 4(b)

This proposed change is administrative in nature and results from a change in the number designation for the Technical Specification (previously T.S.

3.7.A.7.a.(2) to T.S. 3.7.A.7.c).

Item 4(c)

The word "pressure" is inserted into the existing Technical Specification for added clarity. This change is considered to be administrative in nature.

Item 4(d)

This proposed change is similar t.o that found in It.em 4(b). and is administrative in nature. It resul.ts from a change in the number designation for the Technical specification (previously T.S. 3.7.A.7.b to T.S. 3.7.A.7.d).

1-Item 4(e)

This proposed change is a result of the change noted in Item 4(d) and is administrative in nature.

The change incorporates the revised number designation to reflect the change noted in Item 4(d).

Item 5(a)

This change to the bases is provided for clarification and is considered to be administrative. It describes the 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months period during which examinations may be done with a deinerted containment as relaxation from the oxygen concentration LCO.

Item 5(b)

This change to the bases allows for the possibility of making minor repairs during reactor power operation.

4383K

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ATTACHMENT 4 BASIS FOR SIGNIFICANT HAZARDS CONSIDERATION As stated in Attachment 3, Description of Proposed Amendment Request, there are three types of changes associated with this Technical Specification amendment.

First, there are the changes which result from providing an Action statement for oxygen concentration and torus drywell differential pressure, should the LCO's be exceeded.

Secondly, there are administrative changes which result from the addition of the action statement which in some cases, required the renumbering/reformatting of existing Technical *specifications. Lastly, there are changes that have been made to the Technical Specifications and/or bases for clarification purposes.

These too, are considered to be administra-tive in nature.

These changes have been reviewed by Commonwealth Edison and we believe that they do not present a Significant Hazards Consideration.

The basis for our determination is documented as follows:

BASIS FOR NO SIGNIFICANT HAZARDS CONSIDERATION Commonweal th Edison has evaluat.ed this proposed* amendment and determined that it involves no significant hazards consideration.

In accordance with the criteria of 10 CFR 50.92(c), a proposed'amendment to an operating license involves no significant hazards considerations if operation of the facility, in accordance with. the proposed amendment, would not:

._:~

1)

Involve a significant increase in the probability or consequences of an accident previously evalua.ted becau~e: ;

(a)

Power operation is presently permitted with containment oxygen concentration greater than 4% for only 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months subsequent to going to RUN and 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months prior to a reactor shutdown.

The change permits 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months of power operation with the primary containment deinerted unrelated to reactor startup or shutdown to allow personnel to enter the drywell at power.

Drywell entries are made to identify any water leakage, affect minor repairs and enable equipment lubrication.

Drywell entries other than during startup are rare.

The change in time that the drywell will not be inerted during power operation allowed by this proposed change is small.

Additionally, there are currently several other Mark I BWR's that are licensed for operation with a deinerted containment for periods greater than 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

Power operation is presently permitted with drywell to torus differential pressure less than l psid for only 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .subsequent to going to RUN and 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months s* prior to a reactor shutdown.

The change permits 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months or power operation without l psid differential pressure unrelated to reactor startup or shutdown to allow personnel to enter the drywell at power.

There is no change in consequences of relaxing the 1 psid differential pressure because the torus was analyzed for 0.0 psid as part of the Mark I Containment Short Term Program and was found to meet acceptance criteria.

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-~---------=-.::.--- - --- - ---- - --- - - -

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_::-.:.=_~-===---==---=-::--.....:. __ _:_..:::.:__ __ -- --- - - -

Therefore, these changes do not significantly increase the probability increase the probability or consequences of previously evaluated accidents.

(b)

The other changes to the Technical Specifications which include the renumbering of other inter-related portions of the Technical Specifications (which were affected by the proposed change) or are changes that are being sought for clarification purposes.

These changes are considered to be administrative in nature.

2)

Create the possibility of a new or different kind of accident from any accident previously evaluated because:

(a)

The effects of short-term deinerting have been analyzed in the FSAR.

Additionally, the torus was analyzed for 0.0 psid drywell to torus differential pressure as part of the Mark I containment Short Term Program and was found to meet acceptance criteria.

Consequently, the possibility of creating a new or different kind of accident from any accident previously evaluated is unchanged.

(b)

The other types of changes noted in the proposed amendment are administrative in nature.

3)

Involve a significant reduction in the margin of safety because:

(a)

FSAR analyses have shown that for design basis accidents, the long term combustible gas control system (ACAD/CAM) can prevent a combustible gas mixture of 4\\ hydrogen even with a deinerted containment.

Therefore, peak containment pressure is bounded by the FSAR LOCA analysis.

The margin of safety for the torus drywell differential pressure is not degraded as a result of this change because analysis of the 0.0 psid drywell to torus differential pressure concludes that ac;ceptance criteria are met.

Therefore, the pres~µre suppressi9n )s: maintained.

~Hence, the changes do not reduce the margin of safety.

~ ~ (,:.!-'

~ *'

(b)

These changes are administrative and therefore do not impact the margin of safety.

Therefore, since the proposed license amendment satisfies the criteria specified in 10 CFR s*0.92, Commonwealth Edison has determined that a no signi-ficant hazards consideration exist for*these,items.

We further request their approval in accordance with the provisions of 10 CFR 50.9l(a)(4).

4383K

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ML17199U844

Text

SUMMARY

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