ML20125B860

Safety Evaluation Supporting Amend 102 to License DPR-21

ML20125B860
Person / Time
Site:	Millstone
Issue date:	06/05/1985
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20125B843	List: ML20125B840 ML20125B850 ML20125B860
References
NUDOCS 8506110579
Download: ML20125B860 (8)

Text

~

o,,

UNITED STATES 8-NUCLEAR REGULATORY COMMISSION o

D

. I WASHINGTON, D. C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO.102 TO PROVISIONAL OPERATING LICENSE NO. DPR-21 NORTHEAST NUCLEAR ENERGY COMPANY MILLSTONE NUCLEAR POWEP STATION, UNIT NO. 1 DOCKET NO. 50-245

1.0 INTRODUCTION

By letter dated May 15, 1985, the licensee proposed to amend Operating License, DPR-71 by changing the Millstone Nuclear Power Station, Unit 1 Technical Specifications.

The changes would allow periods of up to 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> without drywell to suppression chamber differential pressure of 1 psid (Technical Specification 3.7.A.2.a.) and oxygen concentration less than 4% (Technical Specification 3.7.A.6.a.).

The proposed changes to the Technical Specifications would permit drywell entry at power for the purpose-of performing inspection, equipment adjustments, and maintenance activities. The drywell entry conditions would be limited by personnel access factors including the purpose and duration of the entry, location in the drywell, drywell temperature and as low as reasonably achievable (ALARA) considerations. The proposed change would expand the Technical Specifications to allow containment entry without reactor shutdown as currently required by Technical Specifications 3.7.A.2.a.(1) and 3.7.A.6.b whenever containrent is deinerted with the reactor in the operating mode. The licensee proposed two technical changes, i.e., addition of two new sections:

1.

"Section 3.7.A.2.a.(3) Differential pressure may be less than 1 psid for a period not to exceed 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> for purposes of conductino a drywell entry."

?.

"Section 3.7.A.6.c. Oxygen concentration may be greater than 45 by volume for a period not to exceed 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> for purposes of conducting a drywell entry"; and two administrative changes to renumber affected sections, i.a., Section 3.7 A.2.a.(3) to 3.7.A.2.a.(4) and B.3.7.A.5 to B.3.7.A.6.

A Notice of Consideration of Issuance of Amendment to License and Proposed No Significant Hazards Consideration Determination and Opportunity for Hearing related to the requested action was published in the Federal Register on May 74, 1985 (50 FR 21523).

No coninents or requests for hearing have been received at this tine. However, as discussed belew, racent infomation indicates that unless this amendment is issued prior to the nonnal 30-day waiting period, it is likely that the reactor will be required to shut down.

8506110579 850605 ADOCK 050 g 5 PDR P

t

. 2.0 EVALUATION The licensee has reported that the proposed additional technical specifications presented above allow the same 48-hour period for drywell entry as is currently allowed for shutdown and startup by Technical Specifications 3.7.A.2.a.(1) and 3.7.A.6.b.

The difference is that plant shutdown would not always be required, thereby reducino unnecessary themal cycling of ma.for plant components. The change would make it pemissible to operate continuously at higher stable power levels than the restrictions of Technical Specifications 3.7.A.2.a.(1) and 3.7.A.6.b whereby power level must be decreased to shut down the reactor within the allowed 24-hour deinerted contrinr'ent period and reinerted within a 24-hour period,when the reactor is placed in "run" node. The net effect of the proposed change is to pemit reactor operation ^ at higher power levels with nomal steady operating conditions during the entire 48-hour deinerted containment period.

The increased power level over the 48-hour deinerted containment period represents a neglioible increase in the residual and decay heat levels following the postulated design bases accident and the resultant change in accident consecuences would be insignificant. The probability of an accident during this period is insignificantly smaller with the changes than without the changes because there is less themal (steady vs. unsteady) cycling of major plant components.

Hence, the risk (probability times consequence) remains essentially unchanged. Also, the consequences of the previously analyzed design basis accident have not changed because the conditions for the proposed change remain within the previously analyzed accident (i.e., deinerted without 1 psid drywell to suppression pool pressure differential). The assumed accident conditions, accident probability, and consequences are unchanged. The administrative changes involve sequentfal number changes caused by the insertion o# two new technical specifications and do not affect safety.

2.1 State Consultation and Final No Sionificant Hazards Consideration Detemination The State of Connecticut was notified on May 29, 1985 of the NRC intention to issue the amendment to the Millstone-1 license without waiting for the full 30-day notice period to expire on June 24, 1985. The State expressed appreciation for the thorough telephone assessment of the proposed amendment recuest and expressed no concern over the change. The belt involved has been in continuous operation for more than 300 days.

Large motor-driven circulators control the containnent atmospheric temperature by forcing large volumes of the atmosphere through coolers. Loss of this atmospheric cooling capability due to belt slippage or failure causes containment temperatures to rise to the limiting conditions for operation.

By telephone conference the staf# was informed that, based on the recent containment drywell and centainment cooling systems data, excessive fan belt slippage or failure is pro.4ected before the nornal 30-day prenotice period expires.

It apporrs ir the judgment of NNECO that without the amendnent it would be necessary to shut the plant down because containment temperature and humidity will otherwise reach the operating limits.

On the basis of the information provided by the licensee, the staff has concluded that the proposed change will not increase the number of hours the reactor can operate with deinerted containment beyond these permitted by the current Technical Specifications, and therefore, core safety margins and the risk to the health and safety of the public are unchanged from the previcus!y anely7ed design basis accident. Therefore, the staff concludes that the reouested action does not involve a significant hazards consideration.

For these reasons the staff has concluded that pursuant to 10 CFR 50.91(a)(5) an emergency situation exists in that failure to act in a timely way would result in shutdown of the plant and that the proposed changes should be authorized without waiting for the 30-day notice period to expire.

3.0 ENVIRONMENTAL CONSIDERATION

This amendment involves a change in the installation or use of facility components located within the restricted area as defined in 10 CFR Part 20.

The staff has determined that the amendment involves no signi#fcent increase in the amounts, and no significant change in the types, of any effluents that may be released offsite and that there is no significant increase in individual or curulative occupational radiation exposure. The Comission has made a final finding that this amendment involves no significant hazards consideration end there has been no public coment on such finding.

Accordingly, this amendment meets the eligibility criteria for categnrical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of this amendment.

4.0 CONCLUSION

The staff has concluded, based on the considerations discussed above, that:

(1) because the amendment does not involve a significant increase in the probability or coneequences of an accident previously evaluated, does not create the possibility of an accident of a type different from any evaluated previnusly, and does not involve a significant reduction in a margin of safety, the amendment does not involve a significant hazards considerations,

(?) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (3) such activities will be conducted in compliance with the Commission's reguletions and the issuance of this amendment will not be inimical to the connon defense and security or to the health and safety of the public.

5.0 ACKNOWLEDGEMENT This Safety Evaluation has been prepared by James J. Shea.

Dated: June 5, 1985.

s

L1 N'."

k.

. UNITED STATES

(-

g

, NUCLEAR REGULATORY COMMISSION

. t

.wAsHWGTON, D. C. 20555

^

Docket No. 50-245-t' t

i

~ Mr.: John F.-Opeka, Senior _Vice President

, Nuclear Engineering and Operations

/

Northeast Nuclear Energy Company

, /

Post Office Rox 270

~

/

Hartford, Connecticut ~06141

/

SUBJECT:

-~ REACTOR OPERATION WITH DEINERTED CONTAINMENT DRYWELL~

1

= c

/

l Re:

-Millstone Nuclear Power Statio tinit No.-1 The Commission has issued the enclosed Amendment No.

to Provisional Operating License No. DPR-21 for t)4 Millstone Nuclear Power Station,

-Unit No. 1.

This amendment-is irresponse to your application dated May 15, 1985.

. This amendment changes the/ppendix A Technical Specifications to permit reactor operation with deinerted reactor containment drywell for up to 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />. The changes all,sk safe drywell entry'for the purpose f e formi o inspection,equipmenftdjustments, and maintenance activitie.

d'6n.

information you havp provided, the staff has concluded that the proposed changes will not yesult in more frequent operation with deinerted containment

^

than would result without the changes and that neither reactor safety nor the

-health and safe'ty of the public has been reduced.

A Notice o nsideration of Issuance ~ of Amendment to License and Proposed

- No Signif cant Hazards Consideration Determination and Opportunity for Hearin related to the requested action was published in the Federal Regis_ r-on May'24, 1985 (50 FR 21523). & ::-: :=ts nr ranua-" "

l w, y B a n.a p, e a s s p s }'

W

== n:;hed. Posw-b -to lo cye 30,91 (a)(6) 2

• fU+ % y&A a w.a.e w 4 s M J r

Q3 w qu de,skkaangg &

1m u-a p a pasmm.

h r

f i

e

,,---~,m.,

~a.,

.,,,--n.-,-e v-,e~---c,w-

.,, wen.,

n

. -. - - -.,,y--m-,y---w g-aw.

r ase

/

o UNITED STATES g

E

' NUCLEAR REGULATORY COMMISSION o

3 p

WASHINGTON. D. C. 20555

~s.,*****/

SAFETY EVALUATION BY THE OFFICE OF. NUCLEAR ~ REACTOR REGULATION SUPPORTING AMENDMENT NO.

TO PROVISIONAL OPERATING LICENSE NO.~ DPR NORTHEAST NUCLEAR ENERGY COMPANY MILLSTONE NUCLEAR POWER STATION, UNIT NO. 1 DOCKET NO.' 50-245

1.0 INTRODUCTION

By letter dated May 15, 1985, the licensee propose to amend Operating License, DPR-21 by changing the Millstone Nuclea Power Station, Unit 1 Technical Specifications. The changes would a ow periods of up to 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> without.drywell to suppression chamber ifferential pressure of 1 psid (Technical Specification 3.7.A.2.a.)

d oxygen concentration less than 4% (Technical Specification 3.7.A.6

.).

The proposed changes to the Technical Specifications would permit ywell entry at power for the l

purpose of performing inspection, eq pment adjustments, and maintenance activities. The drywell entry con tions would be limited by personnel access factors including the purp se and duration of the entry, location in the drywell, drywell temperatur and as low as reasonably achievable (ALARA) considerations. The proposed hange would expand the Technical Specifications to allow containment entry thout reactor shutdown as currently required by Technical Specifications

.7.A.2.a.(1) and 3.7.A.6.b whenever containment is deinerted with the r ctor in the operating mode. The licensee proposed two technical changes i.e., addition of two new sections:

1.

"_Section 3

.A.2.a.(3) Differential pressure may be less than 1 psid for a period not o exceed 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> for purposes of conducting a drywell entry."

'2.

"Se ion 3.7.A.6.c. Oxygen concentration may be greater than 4% by volume for a period not to exceed 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> for purposes of conducting a drywel entry"; and

-two inistrative changes to renumber affected sections, i.e., Section 3.7

.2.a.(3)to3.7.A.2.a.(4)andB.3.7.A.5toB.3.7.A.6.

Notice of Consideration of Issuance of Amendment to License and Proposed No Significant Hazards Consideration Determination and Opportunity for Hearing related to the requested action was published in the Federal Register on May 24, 1985 (50 FR 21523). No comments or requests for hearing have been received at this time,tfr %, a., & hu%

Qg rw S ad.dA, % J.,,. o..,

o,.,_ w a y R p -6A h o 3o d e q w Q Gr. L 1. f % <* n O u t W U

" N ?

'~'

).:, 4 4> X T

~

. 2.0 EVALUATION The licensee has reported that the proposed additional technical specifications presented above allow the same 48-hour period for drywel entry as is currently allowed for shutdown and startup by Technical Specifications 3.7 A.2.a.(1) and 3.7.A.6.b.

The difference is that lant shutdown would not always be required, thereby reducing unnecessa thermal

. cycling of major plant components. The change would make it pe issible to operate continuously at higher stable estrictions of Technical Specifications 3.7.A.2.a.(1) power levels than the and 3.7.A.6.b wher y power level must be decreased to shut down the reactor within th allowed 24-hour deinerted containment period and reinerted withi a 24-hour period when the reactor is placed in "run" mode. The n.

effect of the proposed change is to permit reactor operation at hig r power levels with normal steady operating conditions during the tire 48-hour deinerted containment period. The increased power level ove the 48-hour deinerted containment period represents a negligible incre e in the residual and decay heat levels following the postulated desi n bases accident and the resultant change in accident consequences wou be insignificant. The-probability of an accident during this perio is insignificantly smaller with the changes than withcot the changes cause there is less thermal (steadyvs. unsteady)cyclingofmajorplntcomponents. Hence, the risk (probability times consequence) remains ssentially unchanged. Also, the consequences of the previously analyz design basis accident have not changed because the conditions for t proposed change remain within the previously analyzed accident (i.e.

deinerted without 1 psid drywell to suppression pool pressure differe fal). The assumed accident conditions, accident probability, and conse ences are unchanged. The administrative changes involve sequential num r changes caused by the insertion of two new technical specifications and o not affect safety.

2.1. State Consultation and Fi 1 No Significant Hazards Consideration Determination The State of Connecti t was notified on May 29, 1985 of the NRC intention to issue the amen t to the Millstone-1 license without waiting for the (w7,L full 30-day notice eriod to expire on June 24,1985. 6iiWFto issuW j

ttr6~nmendment-in- -timely-way-could_ result-irarunjustified-and possibly i

unplanned shut n of the_ plant-to-adjust-the-belt-tension-on-a-motor-dr4ven fan. The bel involved has been in continuous operation for more than 300 days. L ge motor-driven circulators control the containment atmospheric temperature y forcing large volumes of the atmosphere throug'1 coolers.

Loss of t s atmospheric cooling capability due to belt slippige or failure causes c ntainment temperatures to rise to the limiting conditions for operat n.

Mrg Sue activity inside containment, with the containment f,ully inerted. /

in Ives an unacceptable risk to'th'e health and safetyfof the craftsmen who s

st perfom the tasks. According to the licensee, the,most opportune' time or containment access is June 8'9, 1985. However,/if conti1ued, operation will not ca'use unacceptable degradation of working' conditiors within

\\

containment, ile., too hot or humid, the licenses has agreed 'to delay l

containment deinerting and access to allow the' full 30-day aren'otice period

+

j toexpirebeforeputtingtheamendmentintogffect.

N

x.

"4

' gaa Redau "

}

/~

0d%l 9 aff $bhu /

}h

,/ /g

,,/

q%9'N$

h k

mk/hrkh!-gY,hQ l

%de'4A.ey A za j

kgw m ~

y re

?

~

c.,,y -

MA W

h aJ edad dj + Ada, +a

,f M

W

=

Al 4

Y{Wbf? /L G$uA$2 k

4 u 24-_

w w p N(

A

=

awAJd Q.9;A & suut i

/

afsiain'a t

=

5s i

e

R-

~$E---

p x

y [ (V A L the g oposed amendment request and expressed no concern ove The State expressed appreciation for the thorough telephone assessment On the basis of the information provided by the licensee, the staff hat concluded that the proposed change will not increase the number of)(ours the reactor can operate with deinerted containment beyond those perm,ftted by the

. current Technical Specifications, and therefore, core safety m3fgins and the risk to the health and safety of the public are unchanged fro >n the previously requested action does not involve a significant hazards con,u' des that the analyzed design basis accident. Therefore, the staff conc 1 siderajion.

wu.t puMM -ta 80 CFG So,916t)(5") Ao d.mef pd**4 SsTudacE 4xM asund.

4 For these reasons the staff has concluded that the prpp,osed changes should w, %dr A

be authorized without waiting for the 30-day notice period to expire.

p i(u m t act w.o-.

3.0 ENVIRONMENTAL CONSIDERATION

tedy r.oay

% h s8 components located within the restricted are'a as defined in 10 CFR Pa This amendment involves a change in the installation or use of facility The staff has determined that the amendm9nt involves no significant increase in the amounts, and no significant chan,ge in the types, of any effluents that may be released offsite and thatethere is no significant increase in individual or cumulative occupationaf radiation exposure. The Commission has made a final finding that thiy/ amendment involves no significant hazards consideration and there Jias been no public coment on such finding.

Accordingly, this amendment neets the eligibility criteria for categorical exclusionsetforthin10CFfJ/51.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmental impact stat'ement or environmental assessment need be prepared in connection wi ff the issuance of this amendment.

4.0 CONCLUSION

ThestaffhasconcJded,basedontheconsiderationsdiscussedabove,that:

(1) because the pfendment does not involve a significant increase in the probability or ponsequences of an accident previously evaluated, does not create the po sibility of an accident of a type different from any evaluated previously, nd does not involve a significant reduction in a margin of safety, th amendment does not involve a significant hazards considerations, (2) ther is reasonable assurance that the health and safety of the public will no be endangered by operation in the proposed manner, and (3) such activ fes will be conducted in ccmpliance with the Commission's regulations and he issuance of this amendment will not be inimical to the common de ense and security or to the health and safety of the public.

5.0 ACKNOWLEDGEMENT This Safety Evaluation has been prepared by James J. Shea.

Dated:

t