ML19319C156
| ML19319C156 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 06/07/1977 |
| From: | Stolz J Office of Nuclear Reactor Regulation |
| To: | Roe L TOLEDO EDISON CO. |
| References | |
| NUDOCS 8001310515 | |
| Download: ML19319C156 (6) | |
Text
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,6 DISTRIBUTION Docket File (
Ore NRC POR RVollmer Local PDR MErnst 4
LWR-#1 File WGammill i
JUl. c 71977 Occret :b. 50-346 RBoyd ELD 4
RDeYoung IE (3)
DVassallo roledo ::dicon Cx:;any FWilliams bcc: JBuchanan, NSIC i
Mc: :tr. Wall C. Fce JStolz TAbernatny, TIC Vice President, Facilities LEngle ACRS (16)
Develognent EHylton Edicen Plaza RHeineman 3G0 Itadison Avenue Dross roledo, Ohio 43652 JKnight RTedesco Gentlemen:
HDenton
.30 aIC C : NIALYSIS OF POSTJLATCD "AU STENd.LINE BFFAK ACCICC.*?
Our recent evaluaticns of a pcstulated mainsteaa line break accident inside contair. rent for P.G clants indicate potential concern in two arecs:
(1) tne treatmnt cf non-safery grace ecuirrent in the evaluation of
- cstulatai steamline break accidents inside centaiment.
(2) the envircreental qualification of safety-related equixent located inside centainment that must function during or as a result of a main steamline creak.
l Tnese ccccerns are related to Issue :Ju:tver 1 of 'TJREG-0138 dated ;;cvem-cer 1976 and 12cua Nmrer 25 of I;CREG-0153 dated Dececc.=r 1975. In order tnat we may continue cur generic review of the:e =ceters, we will need
/ cur reccence to cur enclosed recuest for acditional informaticn.
Please advice us witain 14 days after recaict of this letter of your senecule for,creviding us with ' jour restacnse.
Sincerely, Origin.d Signed by John F. Stolz John F. Stolz, Chief Light Water Reacters 3 ranch No. 1 l
Division of Project Manageant
Enclosure:
l Recuest for A.iiitional Information cc: See Page 2
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LWRZ(1, DSS y LEngle:
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JStolz RTedesco 6/ /77 6/. 1177 6// /77 sats >
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NRC FORM 314 (M6) NRCM 0240 D u. s. eov s anusat rai= vine arrics, inte - ese-eaa 8001310M I
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n JUN 0 71977 Toledo Edisen Conparrf !
e ccs: Conald H. Hauser, Esq.
The Cleveland Electric Il1taninatits Cc:r. pony P. O. Box 5000 Clevelard, Chio 44101 Gerald Charnoff, Esq.
Shmt, Pittman, Potts & Troweridge i
1300 :( Street, N. h.
i Washington, D. C. 20036 Iaslie Henry, Cr,q.
Fuller, Seney, Henry and flodge 300 ?.adison A wnee i
ToleJo, Chio 43604 I
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NRC FORM 310 (9-74) NR OE 0240 W u. s. eoven=.esnt poinnne oericas save--
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Request for Additional Information Main Steam Line Break Accident Inside Containment Containment Systems Branch' 6.44 Describe and justify the analytical model used to conservatively determine j
the maximum containment temperature and pressure for a spectrum of postulated main steam line breaks for various reactor power levels.
Interim staff positions regarding postulated main steam line breaks are discussed in NUREG-0138, Issue No. I and NUREG-0153, Issue No. 25.
Include the following in the discussion:
a.
Provide single active failure analyses which specifically identify those safety grade systems and components relied upon to limit the mass and energy release and containment pressure / temperature r
response. The single failure analysis should include, but not necessarily be limited to: main steam and connected systems isolation; feedwater, auxiliary feedwater, and connected systems isolation; feedwater, condensate, and auxiliary feedwater pump trip, and auxiliary feedwater run-out control system; the loss of or availability of offsite power; diesel failure when loss of offsite power is evaluated; and partial loss of containment cooling systems.
b.
Discuss and justify the assumptions made regarding the time at which active containment heat removal systems beccme effective.
i c.
Discuss and justify the heat transfer correlation (s) (e.g., Tagami, Uchida) used to calculate the heat transfer from the centainment atmosphere to the passive heat sinks, and provide a plot of the heat transfer coefficient versus time for the most severe steam line break accident analyzed.
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d.
Specify and justify the temperature used in the, calculation of condensing heat transfer to the passive heat sinks; i.e., specify whether the saturation temperature corresponding to the partial pressure of the vapor, or the atmosphere temperature which may be superheat'ed was used.
e.
Discuss and justify the analytical model including the thermodynamic equations used to account for the removal of the condensed mass from the containment atmosphere due to condensing heat transfer to the
'l passive heat sinks; f.
Provide a table of the peak values of containment atmosphere temperature and pressure for the spectrum of break areas and power levels analyzed; g.
For the case which results in the maximum containment atmosphere temperature, graphically show the containment atmosphere temperature, the containment liner temperature, and the containment concrete temperature as a function of time. Compare tne calculated containment atmosphere temperature response to the temperature profile used in the environmental qualification program for those safety related instruments and mechanical components needed to mitigate the consequences of the assumed main steam line break and effect safety reactor shutdown; h.
For the* case which results in maximum containment atmosphere pressure, graphically show the containment pressure as a function of time; and i
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1.
For the cases which result in the maximum containment atmosphere pressure and temperature, provide the mass and energy release data t
in tabular form.
J.
For the in'strumentation and equipment located inside the containment and required to (1) detect the steam line break; (2) initiate safety l
systems and (3) monitor the course of the accident, provide tne following:
- 1) A description of the tests which were/or will be performed to show that this instrumentation and equipment are/or will be qualified to perform their function before, durirg and after the accident.
Include the spectrum of environmental conditions for which tests were/will be performed and state the acceptance criteria. The instrumentation and equipment to be considered includes, but is not limited to the following:
(a) pressurizer pressure and level sensors and transmitters; (b) steam generator pressure and level sensors and transmitters; (c) main steam line pressure, differential pressure and flow sensors and transmitters; (d) primary system hot leg and cold leg temoerature sensors and transmitters; (e) primary system pressure sensors and transmitters; (g) feed water flow sensors and transmitters; l
(h) containment pressure sensors and transmitters; (i) valve j
operators and position switches; (j) electrical cables, motors and penetrations; (k) containment coolers. Also identify any additional instruments and equipment required.
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- 2) A description of the separation and independence between redundant sensors, cables and other equipment associated with each steam generator and steam line.
- 3) A description of the independence and separation between each steam generator and between each steam line.
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