ML19254E284
| ML19254E284 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 10/15/1979 |
| From: | Baer R Office of Nuclear Reactor Regulation |
| To: | Parker W DUKE POWER CO. |
| References | |
| NUDOCS 7910310415 | |
| Download: ML19254E284 (4) | |
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UNITED STATES fi.()
NUCLEAR REGULATORY COMMISSION P
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CCT A 51979 Docket Nos. 50-369 and 50-370 Mr. William O. Parker, Jr.
Vice President, Steam Production P. 0. Box 2173 422 Soutn Churen Street Charlotte, North Carolina 23242
Dear Mr. Parker:
SUBJECT:
STEAM GENERATOR LEVEL MEASUREMENT ERR 005 (McGuire Nuclear Station, Units 1 and 2)
On June 22, 1979 Westingnouse Electric Corporation reported to us a potential safety hazard under 10 CFR 21. This report addressed errors generated in the staam generator level indication sensors following nigh energy cice break acci-dents inside containment.
Since this matter could significantly effect the McGuire design, we request that you provide us with some additional information described in tne Enclosure.
We request tnat your response be provided no later than November 19, 1979.
This item is,teing carried as Numcer 33 on the McGuire Milestone Chart.
Please let us know if you have any questions regarding this matter.
Sincerely, s
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Robert L. Baer, Chief Light Water Reactors 3 ranch No. 2 Division of Project Mar.agement
Enclosure:
Request for Additional Info rma tion ccs w/ enclosure:
See next pages 4
203 7910310 4-/S
OCT 151979 Mr. William C. Parker, Jr.
Vice Presicent, Steam Procuccicn Duke Power Company P. O. Box 2178 422 South Church Street Charlotte, North Carolina 28242 cc:
Mr. W. L. Porter Duke Power Company P. O. Box 2178 422 Scuth Church Street Charlotte, North Carolina 28242 Mr. R. S. Ho wa rd Power Systems Di vision Wes 'inghcuse Electric Ccrporation P.
. Sox 355 Pittsburgh, Pennsylvania 15230 Mr. E. J. Keith EDS Nuclear Incorporated 220 Montgccery Street San Francisco, California 94104 Mr. J. E. Hough:aling NUS Car;cration 2536 Ccuntryside Soulevard Cl earwater, Florica 33515 s
Mr. Jess' L. Riley, Presiden:
e The Carclina invironmental Study Group a54 Henley Place Charlotte, North Carolina 28207 J. Michael McGarry, III, Esq.
Debevoise 3 Liberman 1200 Seventeen:n Street, N. W.
Washington, C. C.
ZCC36 Rcbert M. Lazo, Esq., Chai rman Atcmic Safety anc Licensing Board U. S. Nuclear Regulatory Con,issicn Wast'qston, D. C.
20555 Dr. Emmeth A. Luecke Atomic Safety and licensing rd U. S. Nuclear Regulatory Car ssion Wasning cn, D. C.
2C555 A
204 Cr. Cace: H. Hand, Jr., Di
- ce Becega Marine Lat of Calif na i
P. O. Ecx 2C e
Socesa Bay, Californ:a 94923 P00R~0 RTE
- T " 5 Gi-Mr. Willian 0. Parker, Jr.
cc: Anthony Z. Roisman, Esq.
Natural Resources Cefense Council 917 - 15th Street, N. W.
Washington, D. C.
20555 Richard P. Wilson, Esq.
Assistant Attorney General State of South Carolina 2600 Bull Street Columbia, South Carolina 29201 9
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ENCI.05URE OCT 151979 f
LEVEL MEASUREMENT ERRORS DUE TD ENVIRONMENTAL TEMPERATURE EFFECTS ON LEVEL INSIRUMENT REFERENCE LEGS On June 22, 1979, Westinghouse Electric Corporation reported to NRC, a potential safety hazard under 10 CFR 21.
This report addresses errors generated in the steam generator level indication sensors following high energy pipe break accidents inside containrent..Furthee; the report implies that previous analyses of peak containcant tempecature 2 and pressure may.'.have been nonconservative.
Breaks of this type can result in heatup of the steam generator level measurerant reference leg resulting in a decrease of the water column density with a consequent increase in the indicated steam generator water level (i.e., indicated level exceeding actual level);
IE Bulletin 79-21 includes further information on this problem and addresses appropriate actions which are to be taken by licensees of cperating plants.
Applicants 'for an operating license are requested to submit a response to the folicwing questions and to revise their safety analysis rcrort consistent with this response.
1.
Describe the liquid level mea'suring syster'.s within containment that are used to initiate safety actions or are used to provide post-accident ronitoring information.
Provide a description of the type of reference leg used 1.e., open colue:n or sealed reference leg.
2.
Provida o evaluation of the effect of postqccident a-bient t rpratur-on the ndicated water level to determine the change in indicated level relative to actual water level. This evaluation must include other scurces of error including the effects of varying fluid pressure and flashing of reference leg to steam on the water level measurem=nts.
3.
Provide an analysis of t@ispact that the leVaTmaasurement err crs in control and protection systems (2 above) have on the assumptions u,ed in the plant transient and accident analysis, This should includa a r: view cf all safety and centrol setpci :ts derived # :m level s nais to verify that the setpoints will initiate the action recuired b.
the phnt safety analyses throughout the ran7e of arbient temperawat encountered by the instrumentation, including accident temoeratorcs.
If tnis ana?ysis demonstrates that levei reasurement errors ar2 gi ca ter tFan assumed in the safety analysis, address the ccrrective action to te taken. T_he corrective actions cen:idwed should include d2rign chInces that could be made to ensera '"at centainment te cerature :-ffec:
are automatically accounted for.
Inesc. :..easures m. y include sspint cnanges as an acceptsble corrective act. ion for the short term.
% ever, s: e fot, cf t r c r Mwe c r crsa tion or Odi fi-= tion to ait 9 = t e cr reduce temperature e.crors should be i ves tigated as a long tei.' sitier 4.
Review and indicate the required revisi ns, as necessary, of es ;; cy procedures to include speci fic infor atica ebtained from the re. :c. and evaluation of Items 1, 2, and 3 to enture that the cperators we b,truc on the potential for and magnitude of err:neous level sicnals.
I..ide a copy of tables, curves, or correction facters that would be applied te post, accident monitoring systems that will be used by plant crere:rs.
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