ML19282B291
| ML19282B291 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 02/23/1979 |
| From: | Baer R Office of Nuclear Reactor Regulation |
| To: | Crews E SOUTH CAROLINA ELECTRIC & GAS CO. |
| References | |
| NUDOCS 7903120489 | |
| Download: ML19282B291 (12) | |
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FEP 2 31979 Docket tio. 50-395 Mr. E. H. Crews, Jr.
Vice President and Group Executive Engineering and Construction South Carolina Electric & Gas Company P. O. Box 764 Columbia, Soutn Carolina 29218
Dear Mr. Crews:
SUBJECT:
REQUEST FOR ADDITI0t1AL ItiFORMATI0t1 Oil THE Fl!!AL SAFETY A?;ALYSIS REPORT (FSAR) FOR THE VIRGIL C. SUMMER tiUCLEAR STATI0ti i ; a result of our review of your responses to the first and second round requests for information, we find that we need additional information to complete our review.
We request that you provide the information listed in the Enclosure by April 15, 1979.
If you are unable to meet this date, please provide your schedule for responding within two weeks of the receipt of this letter.
If you have any questions about t;
- Enclosure, please contact us.
'incerely, NG
,7 Robert L. Baer, Chief Light Water Reactors Branch flo. 2 Division of Project Management
Enclosure:
Request for Additional Information 7903120489
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pj d{'/'ir. E. H. Crews, Jr., Vice President FEB 2 31979 and Group Executive - Engineering and Construction South Carolina Electric & Gas Company' P. O. Box 764 Columbia, South Carolina 29218 cc:
Mr. H. T. Babb, General Manager South Carolina Electric & Gas Company P. O. Box 764 Columbia, South Carolina 29218 G. H. Fischer, Esq.
Vice President & General Cour 21 South Carolina Electric & Gas omnany P. O. Box 764 Columbia, South Carolina 29cio Mr. William C. Mescher President & Chief Executive South Carolina Public Service Authority 223 North Live Oak Drive Moncks Corner, South Carolina 29461 Mr. William A. Williams, Jr.
Executive Assistant to the General Manager South Carolina Public Service Authority 223 North Live Oak Drive Moncks Corner, South Carolina 29461 Wallace S. Murphy, Esq.
General Counsel South Carolina Public Service Authority 223 North Live Oak Drive Moncks Corner, South Carolina 29461 Troy B. Conner, Jr., Esq.
Conner, Moore & Corber 1711 Parnsylvania Avenue, N. W.
Wash nigton, D. C.
20006 Mr. Mark B. Whitaker, Jr.
Licensing and Staff Engineer South Carolina Electric & Gas Company P. O. Box 764 Columbia, South Carolina 29218 Mr. O. W. Dixon Group Manager, Production Engineering South Carolina Electric & Gas Company P. O. Box 764 Columbia, South Carolina 29218 S
Mr. E. H. Crews, J r.
FEB 2 3 1979
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Mr. Brett Allen Bursey
~ Route 1 Box 93C Little Mountain, South Carolina 29076 State Clearinghouse Office of the Governc-Division of Administration 1205 Pendleton Street 4th Floor Columbia, South Carolina 29201 Dr. Lamar Priester, Jr.
Deputy Commission for Environmental Health and Safety South Carolina Department of Helath and Environmental Control 2600 Bull Street Columbia, South Carolina 29201 Chairman Fairfield County Council P. O. Box 293 Winnsboro, South Carolina 29180 U. S. Environmental Protection Agency ATIN: EIS Coordinator Region IV Office 345 Courtland Street, N. E.
Atlanta, Georgia 30308 m
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FEB 2 31973 ENCLOSURE RE00EST FOR ADDITIONAL INFORMATION ON THE FINAL SAFETY ANALYS!S_
REPORT FOR THE VltiGIL C. SUt@tER NUCLEAR STATION m
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FEB 2 3 gg79 i
.022.00 CONTAliCIENT 3YSTE;1S 022.51 It does not appear that the minimum containment backpressure calculation which was used for the ECCS performance evaluation meets the provisions of Branch Technical Position (BTP) CSB 6-1, " Minimum Containment Pressure Model for PWR ECCS Performance Evaluation." Provide the following~:
a) Specify the initiating times for the containment sprays and fan coolers assuming loss of offsite power and startup of the diesel genera to rs. Specify the effective times for actuating these systems assuming offsite power is available, and provide justification for not using these +.imes.
b) FSAR Table 6.2-1 states that there are four fan cooling units.
Provide justification for assuming only two fan cooling units are operational for the backpressure calculation.
c) Specify and justify the heat removal rate assumed for tne reactor building fan cooling units.
d)
Item B.3.b of BTP CSB 6-1 states that the given condensing heat transfer coefficient be applied to all passive heat sinks, both metal and concrete, and for both painted and unpainted surfaces.
Therefore, the heat transfer coefficient to steel containment structures provided in Figure 15.4-8 is not acceptable.
Provide an analysis using the heat transfer coefficient of Figure 6.2-64 to all passive heat sinks as recommended in the BTP.
FEB 2 31979 022.52 It is not apparent that all sources of hydrogen have been assuced in the' combustible gas control analysis.
The analysis presented in FSAR Section 15.4 does not consider hydrogen production from zinc or aluminum based coatings.
Therefore, specify the total area inside containment that is covered by each type of coating, including the ma ss of me tal.
Provide an analysis which includes the effect of these coatings on the post-LOCA hydrogen production inside containment.
Discuss and justify the hydrogen generation (corrosion) rates in the analysis.
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FEB 2 3 1979 130.0 STRUCTURAL ENGINEERING 130.44 Section 6.2.1.3.8.2.3 of the FSAR contains a statement that the 3.8.3 local dif ferential pressures across the steam generator sub-compartment exceed the design differential pressures.
Provide the results of your analysis which show the concrete and steel stresses in the area of the higher pressures.
Also provide the acceptance criteria associated with these stresses and if the calculated stresses are in excess of the allowable provide your rational for acceptance.
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FEP 2 3 199 211.0 REACTOR SYSTEMS 211.21 A deficiency report, dated 10-22-78 and submitted for the Seabrook station, identified an inadequacy in the refueling water storage tank "capaci ty.
The deficiency is related to the remaining capacity in the refueling water storage tank, following transfer from the injection to the rectr-culation mode, and the required operator actions and the time needed to perform these actions relative tc this remaining tank capacity.
To provide assurance that a similar problem does not exist for the Virgil C. Summer Nuclear Station, we request that you provide tne sizing design basis for the refueling water storage tank inclucing the following specific information:
1.
Design allowance for refueling water storage tank a.
Injection requirements (LOCA) b.
Instrumentation error c.
Working allowance d.
Transfer allowance e.
Single failure allowance f.
Unusable volume 2.
Identify the specific functions that the operator must perform followlag switchover from injection to recir-culation mode ar.d )rior to loss of remaining refueling water storage tank capacity.
Also provide an assess-ment of the expected time needed to parform each of these functions.
3.
Provide the remaining usable refueling ;apacity after switchove" from injection to the recirculation operating mode.
Also, discuss whether the unusable refueling water storage tank capacity is the same for the con-tainment spray system as for the emergency core cooling sys tem.
Show that there is sufficient allowance to reduce the potential for vortex formation and entrain-ment of air into the refueling water storage suction piping.
Describe the preoperational test which will confirm that the usable volume is large Enough for sufficient submergence of suction piping at the time of, and just prior to, automatic switchover.
Provide the submergence of the suction pipe at the time of automatic switchover.
Discuss the same concern and testing for the system (s) continuing to pump from tne refueling water storage tank af ter automatic switchover.
Provide the submergence of this piping at its lowest usable level.
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FEB 0 3 N79 4.
Determine the shortest times.available for both a small and large
' break for the following:
a.
The time to automatic switchover from injection to recir-culation operating mode.
b.
The time to use up the remaining refueling water storage tank capacity following switchover.
Justify the basis for these shortest times in terms of the worst single failure.
5.
Identify the automatic features, times, and operator actions required for the containment spray system following a LOCA through switchover from the injection to recirculation mode.
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rF9 2.1 :979 372.0
, METEOROLOGY 372.33 With regard to your response to Item 372.26:
a.
Part Ib states that " seismic Category I ouildings at the Summer site are actually designed for snow.
loadings of 20 pounds per square foot, representi'ng the weight of 40 inches of snow."
Indicate if this load includes consideration of roof shapes and building configuration.
b.
Part 2, which addresses the 48-hour probable maximum winter precipitation, considered precipitation only in the form of snow rather than the more likely combination of snow, sleet, freezing rain, and rain resulting in maximum roof loadings by plugging drains and scuppers.
You state that maximum roof loadings may be mitigated by plant operational procedures "for r3moval of snow from roofs to prevent the buildup of excessive loads." Describe the plant operational procedure requirements for removal of snow from roofs as mentioned in the response to Part 2 of Question 372.26.
372.34 With regard to your response to Item 372.27:
(2.3.1) a.
The design basis air temperatures presented on page 2.3-14 of the FSAR are based on the ASHRAE Handbook, and " represent values that are equalled or exceeded less than one percent of the time."
Discuss considera-tion of persistence of extreme temperatures for engineering design purposes.
For example, of the minimum outdoor air temperature for safety related components located outdoors (-2 F) is exceeded for several hours, cou d safety related equipment be rendered inoperable?
b.
The statement is made Son page 2.3-15 of the FSAR that although the selected design basis temperatures have been exceeded, "the differences are very small and are insignificant for engineering design purposes."
Indicate what would be considered a significant difference betwwen the design basis temperatures and observed extreme temperatures for the purposes of engineering design.
c.
The response to Part 3 cf Question 372.27 discussed moisture buildup in buildings.
However, licensee event reports have indicated failures such as moisture freezing in the main steam isolation valves, ice buildup on the air supply damper to the diesel genera-tor room, freezing of service water valves and trans-mitting sensing lines, plugging of vent screens and filters by ice, and freezing of moisture of off-gas
rrn ? < 1979 stacks result,ing in an explosion in the off-gas building.
Discuss the design considerations of the Summer facility to prevent such occurences resulting from moisture building and freezing tempe ra tures.
372.34 The response to Question 372.29 indicated that for cerain meterorological (2.3.3) conditions the data observed at the location of the meteorological tower "may be somewhat unrepresentative and more fa vorable than actual disper-tion conditions downwind of the reactor building." Discuss how you plan to accoun+. for these unrepresentative and unconservative meteorological conditions in emergency or operational procedures that utilize 4tmo-spheric transport and diffusion characteristics.
372.36 The response to Question 372.30 requires some clarification. Will the (2.3.3) lower wind speed and wind direction, and differential (10-61m) temperature observations be recorded on strip charts on the main con-trol board in the control room? Also discuss the status of the digital recording system to be utilized for the operational program.
372.37 The response to Question 372.32 is confusing.
It is not obvious that the relative concentration (X/Q) values for conditions during inter-mittent releases will be less than the calculated annual average X/Q values. Discuss the methodology by which X/Q values for intermittent releases are determined to less than the annual average X/Q values, and discuss the mechanism to be employed to ensure that planned discharges will be made during periods of favorable meteorological conditions as indicated in the response to Question 372.32.
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CEB 2 3 1979 423.0 Initial Test Program 423.36 We have concluded that Regulatory Guide 1.68.2, " initial Startup Test Pro 9 am to Demonstrate Remote Shutdo.:n Capability for 'later-Cooled fluc' ear Power Plants" (Revision 1, July 1918) and Regula-tory Guide 1.108, " Periodic Testing of Diesel Generator Linits Used as Onsite Electric Power Systems at Nuclear re<.er Plants" (Revision 1, August 1977) are applicable for your facility.
Podify your PSAR to describe how,our initial Lest piogra;a will conform to Regulatory Guide 1.68.2 and Regulatory Positions C.2.a and C.2.b of Regulatory Guide 1.108 or describe how you will provide for equivalent alternative testing.
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