ML19253B729
| ML19253B729 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 03/20/1972 |
| From: | Schierling H US ATOMIC ENERGY COMMISSION (AEC) |
| To: | Deyoung R US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| NUDOCS 7910180716 | |
| Download: ML19253B729 (5) | |
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- e. - ;E"* ' '*?N UNITED STATES 4 ' h,g ATOMIC ENERGY COMMISSION l
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March 20, 1972 R. C. DeYoung, Assistant Director fc, Pressurized Water Reactors, DRL THRU:
Karl Kniel, Chief, PWR Project Branch No. 2, DRL /)
SITE VISIT TO METROPOLITA EDISOS COMPANY - THREE MILE ISLAND SUCLEAR STATION UNIT 1(DOCKET 50. 50-289)
Enclosed is a summary of observations resulting from the site visit-on March 9,1972 to Three Mile Island 1.
The purpose of the site visit was to review the present status of installation of electrical and instrumentation systems, the status of the repair of the ring girder of the reactor containment building, and the installation of the decay
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heat removal and reactor building spray pumps.
A list of all personnel who participated or were contacted during -the site visit is enclosed.
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H. Schierling PWR Project Branch No. 2 Division of Reactor Licensing
Enclosures:
1.
Site Visit Summary 2.
Attendance List 3.
Report on Electrical and Instrumentation Systems Dis tribu tion :
Docket file DRL Reading PWR-2 P. A. Morris F. Schroeder T.
R. Wilson R. S. Boyd' D. J. Skovholt H. R. Denton E. G. Case R. R. Maccary PWR Branch Chiefs R. W. Elecker CO (2)
H. Schierlin, D.
Ross D. Sullivan
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ENCLOSURE I SITE VISIT TO THREE MILE ISLA';D UNIT 1 MARCH 9, 1972 SU' DIARY I.
ELECTRICAL A';D INSTRUMENTATION SYSTE;!S A detailed review and observation of the present state of completion of the electrical and instrurentation systems was conducted by D. Sullivan, DRS.
A report and.his concents are enclosed (Enclosure 3 ).
At the present approximately 35 percent of the cables have been completely installed.
II.
REACTOR BUILDING SPRAY AND DECAY HEAT REMOVAL PUMPS The present state of installation of the reactor building spray pumps (2) and the decay heat removal pumps (2) was observed.
These pumps are located in individual pits and are mounted on a. concrete foundation.
The applicant intends, if nec.essary, to remove this foundation and thus increase the available net positive suction head, !PSH, by 9.6 inches. At the present the suction and discharge lines have not been finally connected to the pumps. While observing the location and layout of the reactor building sump pit S. Delicate, Babcock & 'c.'ilcox, indicated that the minimum sump elevation used in the applicant's latest NPSR calculations (Amendment 23, January 31, 1972) is based on conservative assunptions of spilled water. hold-up in pipes and on various floors in the reactor builiding which results in a waterlevel of 4 feet above the reactor building floor.
III.
REACTOR BUILDING RING GIJ. DER REPAIR The initial construction of the ring girder of the reactor containment building (180* on north side) is defective, containing voids in the concrete.
The continuing repair of the damage was observed.
The repair is perforced by segments of 15 and 30 degrees in three sections defined in Table I.
TABLE I REPAIR SECTIONS Section I:
Lower trumplates, one 30* segment, one 15* segement, concrete replacement in two lifts.
Sectica II:
Upper trumplates, one 30* segment, one 15* segmenr., concrete replacement in three lifts.
52ctica III:
Upper and lower trumplates, three 30* segments, concrete replacement in three lifts.
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. So far the repairs have been restricted to segments in Sections I and II.
Excavation of the voids in these sections is completed, the repair and replacement of damaged rebar is in progress. Concrete replacement began on February 16, 1972. Table II provides a summary of all concrete replacements as of this date including the type and number of rebac repairs performed.
TABLE II CO:!PLETED REPAIRS Section I Section I Section II Section II 15" segment 15' segment 15' seg=ent 30' segment Lift 1 Lift 2 Lift 1 Lift 1 Core samples 3
not 4
9 available Cadwelds 122 23 46 51 Buttwelds 0
0 0
0 Nickweldsyf 0
0 0
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1/ nicks that are 3/32 inch or less in depth are cleaned by grinding and filled by welding if the nicks are in low stress rebar.
13 of these nickwelds were performed on rebar that terminates within the cavity. These nickwelds were executed for welding practice purposes.
The estimated total number of critical rebar (high stress rebar) in the entire 60 degress repair region is approximately 1440.
Applicant intends to completely repair Sections I and II before starting repairs in Section III within about two months.
It eas noted that sete of the cocpleted c'adweld splices that had passed QC inspection had excessive voids or the weld material had squirted beyond the cadweld splice. The applicant indicated that he will inspect the welds again in accordance with appropriate codes.
The epoxy bonding between existing and replaced concrete, as deconstrated by the applicant in mock-op sections, showed no obvious change free a previous observation (See Site Visit Report of November 19, 1971).
The mock-up sections are stored in the open -at the site and are exposed to the same environmental conditions as the reactor building.
IV.
CE"ERAL The followin, schedules for Unit I mnd Unit 2 were provided by R. Heward, Project Manage r, Me t-Ed:
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6 Iteh Unit l' Unit 2 Percent Completion 78 19 Start of pre-op testing started Fuel loading Feb.,'73 July, '74 Start of commercial operation July 7, 1973 November 29,19 7' J. Thorpe, Licensi.ng "anager, GPU, indicated that the applicant intends to request issuance of an early notice as soon as the draf t environmental statement has been issued by the Cc: mission.
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ENCLOSUPI II ATTENDANCE LIST SITE VISIT THREE MILE ISLA';D C;IT 1 Metropolitan Edison Company - General Public Utilities R. Heward W. Guna J. Thorpe T. Hreczuch J. Wright D..Reppert W. Schmauss J. Herbein Gilbert Associates E.
Stauffer W. Sailer J. Smi'th V. Willems United Engineers R. Liscom Babucek & Wilcox J. Hill S. Delicate AEC D. Sullivan, DRS S. Folsom, COI T. Varella, COI
- !. Schierling, DP1 B. Cudlin, DP1 1445 138