ML19309F118

Responds to NRC 800417 Request.Provides Addl Info Re Monitoring to Complete NRC Review of 800401 Response to NUREG-0578,TMI Lesseons Learned short-term Requirements.No Flooding Danger to Hydrogen Analyzers

ML19309F118
Person / Time
Site:	Vermont Yankee File:NorthStar Vermont Yankee icon.png
Issue date:	04/24/1980
From:	Rich Smith VERMONT YANKEE NUCLEAR POWER CORP.
To:	Ippolito T Office of Nuclear Reactor Regulation
References
RTR-NUREG-0578, RTR-NUREG-578 WVY-80-64, NUDOCS 8004280506
Download: ML19309F118 (4)

Text

{{#Wiki_filter:. I ) VERMONT Y AN KEE NUCLEAR POWER CORPOR ATION 'L SEVENTY SEVEN GROVE STREET B.3.2.1 RUTLAND, VERMONT 05701 REPLY TO: ENGINEERING OFFICE TURNPIKE RO Ao WESTBoRO, M ASS ACHUSETTS 01581 TELEPHONE 617 306 901) April 24, 1980 United States Nuclear Regulatory Commission Washington, D.C. 20555

• tention: Office of Nuclear Reactor Regulation Mr. Thomas A. Ippolito, Chief Operating Projects Branch #2 Division of Project Management

Reference:

(a) License No. DPR-28 (Docket No. 50-271) (b) Letter, W.F. Conway (VYNPC) to T. Ippolito (USNRC) dated April 1, 1980 (c) Telecon, R.L. Smith to V. Rooney, on April 17, 1980

Subject:

NUREG-0578 Hydrogen Monitoring

Dear Sir:

In Reference (c), members of the NRC staff requested additional information to enable them to complete their review of Reference (b). These requests and Vermont Yankee's responses are listed below: Question How are the Hydrogen analyzers at Vermont Yankee protected from flooding?

Response

The Delphi (Primary) hydrogen analyzer is located on the 280 foot elevation of the reactor building. Ground level in the reactor building is at the 252 foot elevation and reactor building basement level is at elevation 213. Large floor openings exist between all levels in the reactor building. The results of our evaluation show no danger from flooding exists for this detector. The MSA unit is installed near the ceiling in a corridor leading from the turbine building to the reactor building at an elevation of approximately 260 feet compared to a ground elevation of 252 feet. No flooding danger exists for this instrument. i l 906 800428 0 L

U.S. Nuclear Regulatory Commission April 24, 1980 Attention: Mr. Thomas A. Ippolito Page 2 Question What is the qualification of the Delphi analyzer in regards to radiation exposure?

Response

The Delphi hydrogen analyzer was required by epecification to analyze a sample with an integrated radiation (gamma) dose of 106 rads. The manufacturer has certified conformance to the specification. Question How does the MSA hydrogen analyzer react to hydrogen concentrations greater than 4%?

Response

The MSA catalytic detector is a Series 501 Explosive Cas Detector. We have been informed by MSA that at concentrations greater than 4 percent hydrogen (by volume), the detector will read down-scale. We have also been informed that this model is equipped with a flame arrestor which p rohibits propagation of flame or explosion outside the detector housing, which is explosion proof. Question How are the hydrogen analyzer systems activated?

Response

In the event of a LOCA, plant procedures require that the hydrogen analyzer system be activated immediately through operator action in the control room. Question How long does it take to get a reading from the hydrogen analyzers after they are activated?

Response

The MSA unit provides an accurate reading 30 minutes af ter being activated. The Delphi analyzer will provide an accurate reading within approximately one minute after being activated. In accordance with the NRC's request in reference (c), another copy of the sketch supplied with reference (b) is being forwarded as an attachment to this letter. i l

I U.S. Nuclect Rsgulatory Commission April 24, 1980 Attention: Mr. Tncm:s A. Ippolito Page 3 7 ) We trust this information will enable you to complete your review of our submittal in a timely manner. If you have any questions, please contact us. Very truly yours, VERMONT YANKEE NUCLEAR POWER CORPORATION R. L. Smith Licensing Engiaeer RLS/kaf t

i i ..1 l,1 '5 j, I c ll.

1. y j 'lllI.:f r. ::

3,l ? 'i 73 r-- l*. );

• I s;g

.A 3,I r k g !.w< *, i s i i 13I ]g d sy '7 18 a.hl IE:if'.'l' ] lu"j,j f e a =

p. y g

-Q f l -- -A}-$ f y.,$ s hl ") - hl I d () h- -- - -( Q{p (- -8. ,h l: [ p.gn l'. i.A, {.I. + s e 9 -ag2[.]yf

• 1 n

4 \\ 4; 3 s k... 2 M N --wg *' ; 4".4 % *ti i,j$.

• t 8

8 c: a

intf, 4.

33 .g ,i .4 n' 1 h hl ll D $.--.i [f i, 3 5 i 4.p-l ,3.-c l y J s i i e, e j 'I ,,l.- 1

i f i

~ e.r - s 1 1 "" 5 l 8 I N. ke'-' l 4 'w e jig dj

1. s U

u@ M I vp -~-A 1 :jT, s, 4 ^ l [II @ M 6 ) y s - 11_. 5 -1 "Er t-t d,- r~- 4 y 4,. ne l3 i.W 3 a iA Y (,eab I

- p n

,e a ,s.,,.

1. -hMM b k' l

' dWi - 5,' } } ~, '* 30 ,f d. 3(1 a s s-i 3

5...

smr I -P.- g h!'r--3.-

.pq 3,g j d

s 1 E I '+C F-ei ~~~ t 3t s ! n ), a -[: g !l -- I 3 )

i. a,

, p8 4 1

• :,',q,h 8i 3 k

9 1 ~ i ? 3 Iy m ,p a($ k. b 9 i i v; tj. m ~1 O '., 3. N ;} N a l e iy, ,i 3 .,__, q_, ' d ' '4O j t c < __g l l l l 3 _ _ _ _ _ _ _ _, _ = =}}