ML20006A838

Provides Addl Info Re 891201 Proposed Rev to Tech Specs for Hydrogen Recombiners,Per NRC Request

ML20006A838
Person / Time
Site:	Millstone
Issue date:	01/19/1990
From:	Mroczka E NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
B13424, TAC-75393, NUDOCS 9001300315
Download: ML20006A838 (2)

Text

g -- --

N < L'?

m

ihf, y .

bY General Offices e Seiden Street, Berlin, Connecticut -)

1 UsI. u N e "

- P.O. BOX 270 . -

.awm[ mmuUN

/,. HARTFORD. CONNECTICUT 06141-0270 l

@ k E J e mn co,w.,,;

(203) 665-5000 o1 .i;> t .

a January 19, 1990-  !

o y a Docket No. 50-423 )

, , B13424 Re: 10CFR50.90 ,

[" U.S. Nuclear Regulatory Commission s Attention: Document Control Desk i

Washington, DC(-20555-o

Reference:

(1) E. J. Mroczka letter to the U.S. Nuclear Regulatory Commission, Proposed Revision to Technical Specifications Hydrogen Recombiners, dated December 1, 1989.

Gentlemen: =

Millst'one Nuclear: Power Station, Unit No. 3 Proposed Revision to Technical Specifications 4 Hydroaen Recombiners (TAC No. 75393) ,

t

~

~By ' letter dated December 1,1989 '-(Reference (1)), Northeast Nuclear Energy Company-(NNECO)isubmitted a proposed revision to the Technical Specifications 1 for Millstone Unit No. 3. t

IniJa subsequent: discussion with the Staff,; additional information was l crquested to clarify the changes proposed to-the surveillance requirements for ,

the 2 hydrogen 1 recombiners. The purpose of this submittal is to provide. the

~Staffewiti. the requested information.

1 As stated-. in1 Reference (1), the existing Technical: Specification 4.6.4.2.b.4-requires:the _ hydrogen recombiners be functionally tested, once per 18 months, using Leontainment air at a flow rate greater than or equal to 50 scfm. The proposed change will require testing with a flow rate above the limit speci-

.fledtin;a newly added Figure 3.6-2. This proposed change will now allow NNEC0

~

to conduct this surveillance test during the normal plant operating conditions at any' range of -containment' operating pressures up to and including atmospheric pressure. In addition, 'the proposed change provides a better a representation of.the performance capability.of the hydrogen-recombiner.

As stated in the Final Safety Analysis Report Section 6.2.1.1.2, the Millstone I 1U nit: No. !3 containment. is a asubatmospheric-type containment. During normal operation the containment is maintained at a subatmospheric pressure (typical- e ly 9.0f to 12.0: psia) to limit 'the peak pressure attained during a postulated ,

accident- and to minimize radioactive releases after the postulated- accident.

As stated in Reference (1), NNEC0 performed a new calculation and determined that the minimum acceptable flow rate through the hydrogen recombiner to be E40.5 ~ scfm . at 9.0' psia. An acceptance curve, Figure 3.6-2, was generated to iaccount 'for instrument inaccuracies which increased the acceptable '

surveillance flow rate to 43 scfm at 9.0 osia. This converts to an acceptable L -surveillance flow rate of El scfm at the minimum containment pressure of 010.6 psia.

n >

< OS3G , REV.4 88. 9001300315 900119 PDR .ADOCK 05000423 7 Agd/

/7

% V P PDC ly

i' , . ,

S 3-f (

5 4 U.S. Nuclear Regulatory Commission s B13424/Page 2'

. January 19, 1990-7 We trust- the' Staff finds this additional. information helpful. Should you have

- any additional questions.please contact our licensing representative directly.

Very truly yours, l NORTHEAST NUCLEAR ENERGY COMPANY ,

I i

, E. J. M/6czka~ p ~

( Senior Vice President l cc: W. T. Russell, Region I Administrator .

D. H. Jaffe, NRC Project Manager, Millstone Jnit No. 3 4 W. J. Raymond, Senior Resident Inspector, Millstone Unit Nos.1, 2, and 3 .

~

t

.Mr. Kevin McCarthy,. Director

. Radiation Control Unit o Department of Environment Protection  !

Hartford, CT 06116 ,

--STATE OF CONNECTICUT) '

) ss. Berlin COUNTY 0F; HARTFORD ~)

L

~

Then'. personally appeared before me, E. J. Mroczka, who being duly- sworn,idid -

. state that he is Senior Vice President of. Northeast Nuclear Energy Company, a u

. Licensee herein, that he is authorized to execute and file the foregoing-information in the name and on behalf of the Licensees herein, and that the- ',

statements contained in said information are true and correct to the best of his' knowledge and belief, b AAAh,u- /?Y W":  :

JIotary Ppic ,

MyCcmm!Mn Exsh Ludi31,003 g ,

e & Trv-- r'wr--t--