ML19220B990
| ML19220B990 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 02/25/1974 |
| From: | Tedesco R US ATOMIC ENERGY COMMISSION (AEC) |
| To: | US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| NUDOCS 7904280037 | |
| Download: ML19220B990 (10) | |
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c' m 0 5 *W Docket So. 50-320 Voss A. Moore Assistant Director for Light k*ater Reactors, Creup 2, L PRILDfLIARY REVIE2 0F Td2II MII.; IS'.A:**D STCLIAE STATIrii, Ci!'" 2 Flant Name:
Three Mile Island !!uclear Station, Unit 2 Docket No. : 50-320 Licensing Stage: OL NSSS Supplier: Babcock & Wilcox Architect Engineer: Burns & Roe
' Containment Type: Dry 2esponsible Branch & Project Manager: IXR 2-2; II. Washburn Requested. Completion Date: March 5, 1974 Applicat's Response Dato; 'J/A Review Status: Preliminary Review Couplete As requested by your memorandum dated February if,1974, the Contain= cut Syste=s Branch has perforned a prg11r.inary review of Section 6.2 of the FSAR for the Three Mile Island Nuclear Station, Unit 2.
Based on this revier we have determined that Section 6.2 is not adequately coeplete to allow the initiation of a detailed technical review; however, we reluctantly indicate that in a general and rot overly impressive manner, the applicant apparently has responded to the information requirements of the stat dard format guida. While we recognize the need for a revisien to the guide va also note that our inforr.ation needs are not at all unknown to induatry.
Thus a lack of response to these needs certainly cust no't be overlooked even if one were 'o agree that in a strict".aense, the applicant r<sponded to the guide contents. Needless to say we vill start some kind of a review effort; however, it can only be a *M1 effort until we get sufficient responses to the enclosed information request.
These specific deficiencies have been identified ani. itemized in the en-closure and are sumarized belors 1.
The mumlytical modal, ass.aspcions, and justification regarding the sources and amounts of energy that night be released into the cournivment during reflood and post-reflood phases of the
'ACA.
2.
The description of the model and computer codes used to predict courater.ent subcompartment pressure response analysi::.
3.
The design pressures for courafnr.ent subcoupartments.
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- " Form AEC 318 ( Re. 9-3 )t AECM 0240 e.o c as se e s.ae-o essaea 7001280037,
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4 Tha energy distribution inside the centainr.ent foliceinn a LCC.i.
5.
A contain= cat pressure response analysis for a atean line break.
6.
The description of tne desit,n, test prograno and perforrance specifications of the proposed catalytic raconbiner.
Two (2) e:an-days of effert were expen. icd on t dn prelininary revice.
Scue caseveri was slipped.
Orfd_2! A-A by:
Rcbert L. Tedeseo Robert L. Iedesco, Assistant Director for Containment Safety Directorste of Licensing l'nclosure:
As stated cc: w/o encl.
A. Giambusao V. McDcnald v/ enc 1.
J. F.endrie S. P.anauer J. Glynn R. Ilecker De Eisenhut S. Varga J. Cartar
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REQUEST FOR ADDITIONAL INFORMATION THREE MILF ISLAND NUCLEAR STAT!CN, UNIT 2 DOCKET NO. 50-320 1.
lor the evaluation of contain=ent response following a design basis LOCA, it is not apparent that the additional energy release fro:
steam generators during pcs -reflood period has been included in the containment pressure response analyses. We will need the results of the contain=ent pressure transient analyses for a spectrum of cold leg breaks.
Include the effect of post blowdown energy sources, such as core stored energy and decay heat, pri=ary system etal stored energy, and steam generator stored energy. The analyses should be extended through the taitial blowdown, reflood, and post-reflood phases of the postulated accidents.
2.
For the break producing the highest containment pressure, provide an energy distribution initially, at the end of blowdown, at the end of reflood period, at the time of containment peak pressure and post-reflood of the fellowing energy inventories:
a.
the energy inventories in each cc=ponent of the reactor coolant system, the stea= generators, reactor coolant, steam generator fluid associated =ctals, and refueling water storage tank.
b.
the arount of energy from the sources including decay heat, zirconius water reaction and feedwater.
c.
the amount of.nergy absorbed by each heat sink in the containment, containment atmosphere water, containment atmosphere air-con-tain=ent structures and =iscellaneous heat sinks.
d.
the a=ount of energy removed by containment spray and residual
-heat exchangers.
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, 3.
The following questions relate to the consertativeness of the assumptions used for deter =ining the = ass and energy releases for contain=ent analys is.
Infor:ation should be provided assuming full ECCS operation and for =ini=u= ECCS operation.
Blowdown Provide an anal sis of the nass and energy for a spectrum of f
a.
hot leg and pu=p suction cold leg break sizes using =ethods and assu=ptions that are consertative for containment analysts.
For each break location, the following information should be provided:
1.
= ass release rate as a functica of time; and 2.
energy release rate as a function of time.
b.
Describe or reference the transition boiling currelation used to predict heat transfer fro = the core during blowdown. Define the criteria that were used to establish the conservatis: of this correlation.
c.
Provide the. average core te=perature initially and at the end of blevdown.
d.
Describe how the pri=ary syste= volu=e which is used in calculating the initial liquid mass contained in the pri=ary syste= is deter =ined.
Provide the te=perature assu=ed in calculation of the primary syste= volu=e, and the assu=ed pressurizer water level. Discuss
.the conservatis= of these values fro = the standpoint of contain=ent analysis.
84~321
- e.
For the =ost severe hot and cold leg breaks, provide the values of the heat transfer coefficients used in the stea= generators.
Discuss how these values are conservative for centain=ent analysis.
f.
Provide analeses showing the ef fect of node spacing and nucleate boiling heat transfer coefficients on pri=ary metal heat flew.
g.
Describe the =ethods used to calculate the initial core stored energy used in the contain=ent pressure calculations. Provide values of the initial and decay power level, gap condue:1vity, burnup, densification and fuel ccnductivity.
Discuss how these values are conservative for containment analysis.
Reflood a.
Describe in = ore detail the model used to predict the = ass and energy release to the contain=ent during the reflood period.
Discuss the conservatis= in the model with respect to =aximizing the energy release to the containment.
Include the assu=ptions
=ade regarding all energy sources, the flew resistance in the broken and intact loop, and the specific volume used in each flow element.
b.
Discuss the assumptions =ade in the reflooding calculation re-garding steam condensation by the e=ergency injecticn water.
If condensation is assumed, provide justificatien based en applicable experi= ental data; 1.e.,
data corresponding to the conditions in the pri=ary syste=.
Provide the results of a sensitivity analysis 84 322 M
showing the = ass and energy released and the effect on contain=ent pressure if:
(1) no condensation and partial ECCS operation is assu=ed, (2) no condensation and full ECCS operation is assu=ed, (3) condensation and partial ECCS operation is assu=ed, and (4) condensation and full ECCS operation is assu=ed.
c.
Discuss the assu=ptions =ade regarding separation of entrained liquid leaving the core during the reflooding period. We believe a conservative approach would be to assu=e no liquid separation so that all liquid leaving the core would enter the steam generator and be available for heat.
d.
Discuss the assumptions made in calculating the carryout fraction from the core (ratio of core exit flow to core inlet flow) during reflood. These asst =ptions should be justified by co=parison with the results of the FLIC'd! experi=ents for average core conditions during re.ilcod.
We believe a carryout rate fraction of approxime.ely 0.8 would occur until the 10-foot level in the core is covered.
e.
Assumh g =axi=u: ECCS, provide the = ass and energy release rates as a function of ti=e.
f.
Assuming =ini=um ECCS, provide the = ass and energy release rates as a function of ti=e.
Post Reficed a.
In the post-reflood phase of the LOCA for cold leg breaks, when the 84-223
% core has been recovered with water, a two-phase mixture of steam and water will be generated.
Provide an analysis showing height that the two-phase =1xture will rise above the core.
If any water is calculated to enter the steam generator, provide the = ass and energy release rates to the containment as a function of tine.
b.
Describe in detail the analytical models used to calculate the additional =a'as and energy relcace to the containment during the
. post-reflood period after the core has been recovered with water.
c.
Provide a list of para:eters used to determine the rass and energy release during the post-reflood period.
This list should include the void ftaction and static liquid head in the downcouer, core, upper plenum and steam generator.
For the het legs. steam generators and cold lags, provide the steam flow rate and pressure drop.
d.
Provide or reference all heat transfer and fluid flow correlatico" used in the analysis.
4.
State the =inimus containment backpressure that has been used in the analysis of the e=ergency core cooling syste=s.
Justify this value to be conservatively lcw by describing the conservatiss used in the assumptions of operating containment conditions, codeling of the heat sinks, heat trar fer coefficients to tra heat sinks, heat sink surface area and any other parascter assu=ed in the analysis. Provide the containment pressure, temperature and su=p te=perature response for the
=ost conservattve assu=p tions.
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. 5.
Related to subco=part=ent pressure response analysis:
Describe the analytical =edel in detail, asse=ptions and appropriate a.
b as er, used in calculating the subec=part=ent pressure respense.
b.
Describe the nadalization sensitivity studies perforced to deter =ine the =ini=u= number of volu=e nodes required to censervatively predict the =axi=u= pressure for each subec=part=ent.
The nodalizatica sensitivity studies should include consideration of spacial pressure variation in the axial, radial, and circu=ferential directions.
Pro-vide scheaatic drawings of each subcompartment shewing the general arrange =ent of the subcc:part=ent structures, cc=ponents, piping, other =ajor obstructions, the nodalization, and the connecting flow paths between volu=e nodes.
c.
Specify the nadal volu=es, flcv coefficients ad flew areas used to calculate the flow between nodal volu=es.
Thic. infor=ation should be of sufficient detail to allow confir atory aalyses to be perfor ed.
d.
Clarify the =anner in which the ficw coefficients vere calculated.
e.
Graphically shcw the pressure variatica with time for each sub-compartment. The - h u= pressure nodal volu=e anc other represent-ative node pressures should be included.
f.
Discuss the =anner in which =ovabic obstructions to vent flow (such as, insulation, ducting, plugs, and seals) were treated.
Include analytical justification if credit is taken for the re= oval of such ite=s to obtain vent area.
84 4+Ad9,tr-M g.
Provide analyses of the pressure differentials for the pressurizer enclosure and pipe annulus in the biological shield.
h.
Provide both the design pressure and the calculated transient pressure response for each of the subco:partments analyzed.
Provide the mass and energy blowdown rates in tabular for=, from 1.
ti=e zero to about 1.5 seconds at approximately 0.05 second inter-vals for the 11=iting case 'a each subcompartment.
6.
Infor=atien should be provided for a containment presotre response analysis of steam line and feedwater line break accidents to include the following:
a.
The = ass and energy release as a function of time.
b.
The to.tal = ass and energy released into the contain:ert.
c.
A description of and justification of all the assu=ptions used to predict the mass and energy release.
d.
A detailed discussion of the analytical model used to predict blewdown flow rate and energy.
7.
Provide the method and results of analysis of the jet forces used in establishing the structural loads within the centain=ent.
8.
Provide the following infahnation regarding the generation of hydrogen following a design basi; loss-of-coolant accident:
a.
Graphically shoe the integrated hydrogen productica (f t ) within the containment as a function of time for each of the potential sources of hydrogen; i. e,., radiolytic deco: position of water, 5%
zirceniu=-water reaction, evolution of entrained hydrogen in o p - <~ c C
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-a-pri=ary coolant and alu=inu= corrosien.
b.
Graphically show the assu=ed cor csica rate of alu=inu= as a function of time.
c.
A discussion of the =agnitude of hydregen of f-gassing expected to occur frc= zine having paint pri=ers and top coatings used in the contain=ent and the analytical and experi= ental bases to support thest. exp ec.'ations.
Include the source of hydrogen as applicable in the analysis requested above.
d.
Provide a listing of the cinc and alutinu= cc=penents within the contain=ent, as well as the mass and surface area of these ec=ponents.
9.
A catalytic recc=biner is proposed for use in the hydrogen control syste=.
The FSAR does not provide ruf ficient infor=ation related ta the design, testing, and performance capability of the system. Frovide this infor ation, together with a detailed discussion of the develop = ental and test progra= that was conducted to de=cnstrate the perfor ance capability of the system.
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