ML20024G637
| ML20024G637 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 08/21/1975 |
| From: | Ziemann D Office of Nuclear Reactor Regulation |
| To: | Mayer L NORTHERN STATES POWER CO. |
| Shared Package | |
| ML20024G638 | List: |
| References | |
| NUDOCS 9102130547 | |
| Download: ML20024G637 (4) | |
Text
T DISTRIBUTION Dockct NRC PDR Local PDR M)G ; 3 1975 ORB #2 Reading KRGoller TJCarter bucht ho. ! 0..'01.
OELD OIf E (3)
DLZiemann BCBuckley Northern States Power Company RMDiggs ATIN :
P.r. L. O. May o r yggeggo Liirector of Nuclear Support JRBuchanan Services TBAbernathy 414 Nicollet Mall SVarga l'inneapolis, Minnesota 55401 ACRS (16)
DEisenhut Cent lere:
Jur on;,oing revie.. of your submittal entitled. "Anticipt.ted *1ransients
.iitliout Scram Study for the Monticello Generating Plant," which was forwarded to hnC on April 1.1975, indicates that additional informrition, j
described in 11a ( ncir3 arc, is requircJ for us to co:rplete our evcluation.
.c beju vr ti. :
t...,reaa..iiity of an anticipated tratsient without s e rm..
o) es e : at t..e enticello facility is sufficiently high that desien
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.c.1d ot u.f] ec..ua c J to rcJuce thc p obu'..ility or evnn-qucnces of en I.T,5 event, tiithin 45 days of receipt of this letter, you me reqeented to provide the inforr.ation described in the enclosure, n description of your propost d riodifications and a schedule for 1:plementation.
Sincerely.
Original Cicned 1:r:
Dennis L. Zienann b _. -
Dennis L. Z.icuann, Chief Operating, lienetors ur:dich #2 Unision of Reactor Licensing, 1.nclos ure i t quest f or AdJ.i t ion: 1 Infor.ation cc r/ci.clonu,
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4 AUG 211975 Northern States Power Company i
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ec t/cnclosure:
1 Arthur P.enquist, Esquire The Environmental Conservation Vice President - I aw Library i
f;arthern States Power Company Minneapolis Public 1.ibrary 414 Nicollet !!all 300 Nicollet Mall Hinneapolis, Minnesota 55401 Minneapolis, Minnesota 55401 Gerald Charnoff Shaw, l'i t tnan, Pott s 6 3
Troubridr,e 91.
17th Street, N. h'.
j h'ashington, D. C.
20006 l
llau; rd J. Vo;;el, Esquire 4
1.cpal Counsel 2750 Dean Parkway Minneapolis, flinnesota 55416 1
Steve Gadler 71.'O Ca r t ( r An m.
- i St. Paul, ".i nne
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55108 Mr. !)a ni c ) L.1ich)
Assi st an t City Attorney 638 City 11011 St. Paul, Minnesotr 55102 Mr. Kenneth 11;ugan linvironn.ent al P1anninj' Consultant St. Paul City Plann.ing 4 21 Wa b.i sha Street St. Paul, Minnerein 55102 Sandra S. Gardebring l
Special Assistant Attorney General Counsel for Minnesota Pc11ution Contrei A;'ency 1935 W. Countv Iload D2 llo s ev il l e, Minnesota 55113 4
Anthony Z. Ilois' ann, Esquire i
1;erlin, 1;oisnan and Kessler 1712 N Street, N. h'.
Washinnt on, D. C.
20030 1
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N010lfEru S'i/JTF." PO'..H Co.:l M MONTICELLO NUCLLAR GENEPATING PLANT j
DOCKET NO. 50-263 l
REQUEST TOR ADD]TIONAL INPOR'iATION 1
Provide the peak toru water terperature reached during the 3.
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MSl\\' closure A'l hS.
Provide and justify a torus water temperature limit.
If the calc.ulated temperature exceeds the limit, discuss l
the plant modifications needed to Leep torus unter temperature below the proposed limit.
If the peak torus water temperature i
exceeds 170*F discuss plant modifications needed to keep this l
temperature below 170*F.
l 2.
The analysis, as described in the Monticello ATh's report, takes credit j
for the operator initiatin:; the standby liquid control (SLC) system five minutes ef ter the ATW event.
Discuss the indications available to the operat or to asturc this manual initiation of the SLC.
4 a
3.
In figure 4-3 the relief valve flow oscillates between about 3,000 and 7,000 lb/see fron about 30 seconds to 95 seconds after the AThS.
At about.108 deconds the relief valve flow begins to oscillat e between 3,000 and 14,0f)0 lb/sec.
Explain this difference in the peak 2elief salve flow.
2 f
p..c.ent sodi g nia' orate solution 4.
L 'l e f.n j.. ; c
- a.c 2 un.
concentratien versus r et tant volume in Figure.
4.1.
The l
concent ra t i er. vor.i e f ra l u. v. t o 21. *i.
Perfor a 1he analpis j
using each of these concent rations. Justify the use of IM as an initial conditica listnl in *lable 3-1 of NLlK)-20S40.- Also j
justify the poison react ivity worth and.specify the reactor i
ves s el volur.2c.
- 5.. In Section 4.4 of the Technical Specifications a minimum flow 4
rate of 24 r; for each of the standby liquid control system pumps ic list ed as a turveillance requirer ent.
Perform the analysis using this value.
In Table 3-2 of NEDO-20b46 a 28 gpm flow rate per pump is list ed.
Provide your basis for using this.
value in your analysis.
Specify the total volume of poison in-jected following the ATWS and indicate the required volume for both hot shutdown and cold shutdown.
6.
It is stated that no accounting for possible non-honorenece I
mixing was made since this would take a detal. led evaluation.
!!owever, GE stated at a meeting with the staff on August 7, 1974, l
that tests were being conductrd on borated water mixing phenomena.
Demonstrate that your assumption of uniform mixing is consistent with the experimental data. Otherwise, perform a sensitivity l
study to Show the effects of non-homogeneous mixing of the liouid poison, varying the mixing efficiency from 50% to 100%.
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4 7.
The staff has submitted to General Electric questions on NEIO-20626 (letter from V. Stello to 1. Stuart, January 28, 1974, and letter from W. Butler to I. Stuart, April 9,1975, copies are l
enclosed).
Respond to the following questions as they apply to Monticello:
1, 4, 5, 6, 9, 12, 13, 16, 17, 310.1, 310.3, and 320.5.
8.
Provide the bases for assuming thirty seconds for transport time of the sodium pentaborate solution from the storage tank to the vessel and for the liquid to become effective in the core.
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