ML19220B486
| ML19220B486 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 04/28/1975 |
| From: | Washburn B Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7904260383 | |
| Download: ML19220B486 (5) | |
Text
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UNITED STATES NUCLEAR REGULATORY COMMISSION W ASHINGTON. D.
C. 20555 Dcchet No. 50-320 April 28, 1975 DCCKET NO:
50-320 APPLICANTS:
Metrcpolita:. Edison Company Jersey Central Power & Light Company Pennsylvania Electric Company FACILITY:
Three Mile Island Nuclear Station, Unit 2
SUMMARY
OF MEETING, APRIL 17, 1975, WITH APPLICANTS TO DISCUSS CON"'AINMENT SYSTEMS QUESTIONS Members of the Nuclear Rt Otor Regulation (NRR) staff met with representatives of the applicants in Bethesda, Maryland, on April 17, 1975, to discuss questions on containment systems analyses.
A list of attendees is attached.
Discussion Summarv 1.
Subccmpartment pressure response analysis Our review of the FSAR up to and including Amendment 26 indicates that the applicants ' responses to cur first-round question 03.1 and to a related acceptance review question, 9-5, are incemolete.
The applicants have not discussed the nedalization studies performed to determine the minimum number of volume ncdes required to conservatively predict the maximum pressure in each subecmpartment.
The applicants indicated that the study has been done, but they did not submit the justification for the selected number of nodes.
The staf f stated that a plot of wall leading or peak loading vs number of nodes should be included in this discussion.
The applicants were asked to provide detailed plan and section drawings of the subecmpartment structures chewing nedalization, nedal net free volumes and interconnecting ficw path areas.
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. The applicants stated that they will submit blue line ccpies of the detail drawings used in the analysis.
The applicants were requested to send these with a transmittal letter which references the forthecming formal request.
The applicants were asked to identify, by type, the design breaks listed en page S2-134b of the FSAR and to justify, f or each subecmpartmen analysis, any assumed breaks less than dcuble-ended.
The applicants were asked to proside and justify the values of vent less coefficients and/or friction facters used for all cavities or subecmpartments.
The staff indicated that coef ficients that are conservative for one nede may not be conservative f or another nede.
The staff is satisfied with this information submitted for the reactor cavity and stated that the same information should be provided for other cavities.
The staf f asked for information on the analytical treatment of movable obstructions to vent flow.
The applicants stated that there were no novable cbstructions e:< cept those in the reactor cavity.
The applicants were asked to provide a table of mass and energy blcwdown rates for each limiting break.
Blcwdown should be covered frca time zero to about 1.5 seconds at approximately 0.05-second intervals.
Table 6.2-17, for example, did not provide sufficiently fine time steps.
B&R did a linear interpolation of the given blewdown rate data and performed the analyses using finer time steps.
The resulting analysis assumption of blewdown rate in the first time increment is not believed to be representative of the actual rate.
The applicants were asked for a pressure analysis of the steam generator support skirt assuming a pump suction line break inside the skirt.
The applicants stated that they had not regarded this as a subccmpartment.
The stafi stated that they needed the same information as requested for subccmpart-ment analyses with the exception that nodalization studies are not required for this analysis.
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- The staff asked for information, in addition to that sub-mitted in response to question 03.1, f or the reacter cavity analysis.
The applicants stated that they would supply the necessary supporting detailed drawings, that they would justify the assumed break *ype and area, and that they wculd submit analyses concerning the missile effects of shield plugs.
The staff stated that they are concerned about delayed opening of shield plugs and that a description of the medel used for pl-g openir.g is needed.
The staff stated that the applicants need to justify all assumed movements of insulation which increase vent areas er alternatively the analyses need to be done assuming tPat this insulation does net move.
The staff is concerned that a vent space may le blocked by insulation which moves.
The staff asked the applicants to resolve the inconsistencies between analysis resu.ts obtained by using ccmputer codes PEAK and CONTEMPT.
The staff pointed oct that the applicants' maximum calculated differential pressu':es, for some of the subccmpartments analyzed, are much higher than the design pressures.
In order to ccmplete the evaluation of the structural design adequacy, based en subecmpartment pressure analyses, it is vital that the aplicants respond ccmpletely to the staff's concerns and need for additional information.
The staff needs to prcmptly evaluate the applicants ' responses to the information requests discussed at this meeting as a prelude to the structural evaluation.
2.
Containment Pressure Response Analysis The staff asked for information, in addition to that submitted in response to questien 03.3, on heat transfer ccefficient correlations and asked that the Tagami and Uchida correlations be used to revise the response to quesu.vu 02.4 The staff stated that the applicants' responses have not adequately described the calculational method and assumptiens used in the main steam line break analysis which establishes containment maximum pressure and temperatures.
The staff expanded on the detail required for adequate response to acceptance review question 9-6.
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ECCS - Containment Backpressure The applicants have no+
ovided a minimum containment pressure analysis for L performance evaluation.
The staff originally addressed this requirement in Acceptance Review questien 9-3.
A formal second-round question anu 3 ranch Technical Position CSS 6-1 will address chis concern and provides additional guidance for the performance of this analysis.
4.
Combustible Gas Centrol Requirements for the hydrogen reccabiner were discussed and the staf f stated that the AI recombiner is still under review.
The applicants stated that their hydrogen gas monitoring system would use grab samples and laboratory gas chroma-tcgraph analysis.
(Section 6.1.1.4 of the FSAR states that the containment atnosphere will be continuously monitored to determine hydrogen concentration.
The applicants should resolve this difference and clearly demonstrate the exten-of ccmpliance with the position in Regulatory Guide 1.7.)
5.
Containment Purge The staff asked for an analysis showing the amcunt of cen-tainment atmosphere that would be released to the environment when assuming the containment purge and vent valves to be open at the time of a LOCA.
6.
Leak Detection The staff asked the applicants for discussion of their capability to detect and to inform the operator of leaks in ESF lines inside the containment.
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W. Washburn Project Manager Light Water Reacters Branch 2-2 Attachment d(mp ' - L ' l ' !d t t
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_A _T T_ _E _N _D _A _N _C _E CONTAINMENT SYSTEMS MEETING April 17, 1975 NAME AFFILIATION A.
W.
Hagstrca B&R N.
L Lacy B&R J.
R.
Ellwanger B&R J.
M.
Vann GPUSC J.
KunJ:el GPL F.
J.
Patti B&R D.
Shum NRC C. Grines NRC-CSB T.
Greene NRC-CSB J.
Shapaker NRC-CSB T.
Hsu B&R A.
Zallnick B&R J.
P. Mccre GPUSC
- 3. Washburn NRC R.
Gido NRC-CSB
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