ML19326A032
| ML19326A032 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 10/21/1976 |
| From: | Stolz J Office of Nuclear Reactor Regulation |
| To: | Roe L TOLEDO EDISON CO. |
| Shared Package | |
| ML19326A033 | List: |
| References | |
| NUDOCS 8001310607 | |
| Download: ML19326A032 (5) | |
Text
f g-b bistribution Docket Files ELD f4RC PDR IE (3)
Local PDR C. Thomas OCT 9
F. J. Williams Docket do. SJ-340'/
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J. Stolz L. Engle E. Hylton R. Heineman Toledo Ediscn Comcany D. Ross ATT;i: fir. Lowell E. Roe J. Knight, SS D*A D D
' 3' Vice President, Facilities R. Tedesco
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Development H. Denton Edison Plaza V. A. ficore 3GJ liadison Avenue R. H. Vollmer Toledo, Ohio 43652 M. L. Ernst W. P. Gamill ntkmen:
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J. R. Buchanan, NSIC T. B. Abernathy, TIC
.~E;LEST FDR ADCITI0 lAL IilFORPATICil (LA'/IS SESSE, LilIT 1)
Uur evaluation of tne Davis Besse, Unit 1 (08-1) Final Safety Snalysis Re;crt as revised threugh Revision '!o. 20 (July 30,137C) recuires additional information in order to cceplete our revim. The request for additional information proviJed in Enclosure 1 to tais letter has been discussed with you in a series of telephone conversations in Auqust and Septemoer 1975 and a draft reauest for information (as provided in Enclosure I to this letter) was telecocied to you on Scotmber 32, H76. Also, 'tr. L. Engle, the Licensing Project 'fanager, discussed eacn iten in Enclosure 1 with lfr. E. *:ovak, General Superintendent,
%er dngineering and Construction, at a site visit on October 6,1976 As you hcou, we are calculating differential pressurcs that. exceed desi Jn values for tne reactor cavity and staan gencratcr ccrrir'.nants.
urcn :xaainarioa of plan and devation drawings, we Sava detemire! that you nave calculated incorrectly certain vent areas.
In our series of discussions with you regarding these natters you have anreed to su! nit a revised reactor cavity analysis using the ;crrect veni: area data vr!
alsa provide appropriate 38-1 inertial tern data (L/A).
We feel cartain tnat peak calculated differential cressures fcr the reactor cavity will exceed design conditions unless the basis for assuning a 14.14 ft2 longitudinal split in the hot leg is re-exanired.
Our discussions with you indicated your plans to suhnit additic'al infomation regarding postulated pipe break configurations and sizes for the reactor cavity analysis. Also, you have indicated your intentions to adopt a similar approacn for the steam generatar compartment analysis, snould that become necessary.
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4EC.313 (Rev,9 33) AECM 0240 A" w s. eOVE RNM ENT FfttNTINe OFFICES t e?4.Sae.t ee 8001310 [O 7 g
Toledo Edison Company Your Revision ;'O presented a revised thermal analysis of the shield building following a LOCA whica increased the shield building depressuri-zation time from 65 seconds to 12.33 minutes. Before we can conclude on the accectability of your revised shield building analysis additfor.31 infomation is required. The request for infomation concernica these matters nave been discussed with you;previnusly.
We have revicwed your plans for operacion of the containment purge system during normal plant operation. As first provided to you in draft fom on September 30, 1976, and in ensuing discussions, you have been advised that it is the staff positien that unless demonstration is provided that the radiolcgical consequences of unlinited purging would be witain 10 CFR Part 10 values following a costulated LOCA, that the purce system operation for Davis Besse, Unit 1 be limited to less than CD 1 curs ror
/ ear (s 15 of the time per year). Thernfore, we require you crovide the analysis as delineated in BTP CSC 6-4, "Contaiment Purcing During Momal Plant Operation," or agree to limi ; urging operating to less than 90 hours0.00104 days <br />0.025 hours <br />1.488095e-4 weeks <br />3.4245e-5 months <br /> per year (.' odes 1, 2, 3 and 4).
If you so decid to adopt the 90 hours0.00104 days <br />0.025 hours <br />1.488095e-4 weeks <br />3.4245e-5 months <br /> per year for purge system operation, we will include this limitation in tne plant tect.nical specifications.
The request for infomation nrovided in Enclosure 1 regarding Contairmnt Leak Tes;irg Tecnnical Specifications have been discussed wita you previously.
S6ca these ratters have been identified to you over a ceriod of tim, we request that you provide the infomation as ideni.ified in F-closure 1 no later thaa Novemoer 5, 1976. Please advise us within 3 days aftar receipt af this letter of ycur plans to meet the above date or nrovi!e us with a different sem.dule in crder that we may adiust our scnt-Niinq accordingly.
Please call us if you nave any cucations concerning tnese natters.
Sinccraly, Driginni ElguedId John F.Stola j John F. Stolz, Chief Lignt Water Reactors Branch Mo.1 Givision of Praject an1gement
Enclosures:
1.
aesuest for ?dditional Information g
2.
Branch Technical Position CSB 6-4 10 cc: See page 3
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Toledo' Edison Company 3-cc: Mr. Donald H. Hauser, Esq.
. Too Cleveland Electric Illuminating Company P. O. Box 5300 Clevelar.d Ohio 44101 Gerald Charnoff, Esq.
Shaw, Pittman, Potts and Trowbridge 1J00 M Street, N. W.
Washington, D. C.
20036 Leslic Henry, Esq.
Fuller, Scncy, Henry and Hodge 330 Madison Avenue Toledo, Ohio 43t,04 4
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ENCLOSURE 1 DAVIS BESSE fl0 CLEAR PO*.!ER STATION. UtlIT 1 C0 4TAlt.NUIT SYSI NS SRAiCH REQUETT FOR ADDITIO!;AL IhF0P.MATION 1.
In the revised shield building analysis, the emergency ventilation system fans are assumed to start in 16 seconds following a postulated loss of coolant accident. Discuss how the actuation time was established and justify that it is conservative. Ccnsider loss of off-site pcwer, startup and sequencing of diesels, the ' time delay for setpoints to be reached, and made of fan actuation (manual or 3-automatic).
If the fan actuation time of 16 seconds is shown to be non-conservative, provide a reanalysis of the shield building pressure transient following a LOCA.
2.
During a shield building pressure transient folicwing a loss of coolant accident, themal expansion of the steel containmant vessel results in a reduction of the annulus volume and an increase in the heat transfer surface area between the containment and the shield building. Both of these effects tend to increase the pressure en the shield building.
Provide justification for the assumption made in the revised shield building analysis (see Page 6-36b cf the FSAR) that both of these effects are ccmpensating and that their combined effect is negligible.
3.
Identify the systems or portiens of systems which will be vented and drained during a Type A test as required by Appendix J to 10 CFR 50, and include this infomation in the proposed Technical Specifications.
Systems that will not be vented or drained should be identified and the reasons for not doing so should be provided.
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The proposed Technical Specifications specify an overall air lock leakage rate limitation of 0.05 La at Pa (38 psig). Since the air lock is included as a potential bypass leak path, this limit conflicts with the maximum allowable bypass leakage rate of 0.015 La.
Provide an acceptance criterien for the overall air leck leakage rate that does not ccnflict with the maximum allcwable bypass leakage rate.
In addition, the proposed Technical Specifications specify that periodic leak testing of the air lock door seals should demonstrate no detectable seal leakage when pressurized to Pa without the use of "strongbacks,"
and that leakage has been detected between the door seals when pressurized at a reduced pressure. Therefore, propose a method of leak testing the volume betveen the dcor seals at a reduced pressure and justify the test pressure.
Provide the equations that will be used to extrapolate the leakage rate to Pa, and. justify that it is a conservative f
method.
In addition, specify and justify the maximum allowable, extrapolated leakage rate at Pa.
5.
The proposed Technical Specifications require some testing of the emergency ventilation system. Mcwever, it is not clear that the testing will verify the acceptability of the system performance.
Identify the parameters to be monitored and specify their limiting values, for the purposa of justifying the calculated 740-second depressuri:aticn time for the shield building.
Propese a technical specification dich identifies the criteria for the acceptable performance of ':he emergency ventilation system.
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