IR 05000289/1975012

IE Insp Rept 50-289/75-12 on 750611-12.No Noncompliance Noted.Major Areas Inspected:Secondary Sys Safety Valve Exhaust Pipe & B Decay Heat Removal Cooler Outlet Valve Support Repairs

ML19256D603
Person / Time
Site:	Three Mile Island
Issue date:	06/19/1975
From:	Durr J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To:
Shared Package
ML19256D602	List: IR 05000289/1975012 ML19256D601
References
50-289-75-12, NUDOCS 7910190566
Download: ML19256D603 (7)

Text

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IE:I Form 12 i

. (TanJ5) (Rev) !- ' ) i- \\. d f I-U. S. NUCLEAR REGULATORY COM111SSION g.- E OFFICE OF INSPECTION AND ENFORCDIE!Tr IT~ j:.- {__

REGION I

y= . - , F.. IE Inspection Report No: 50-289/75-12 Docket No: 50-289 i:l Licensee: Metropolitan Edison Company License No: DPR-50

E .P.

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Box 542 Priority: I... ' -- _ - Reading, PA C Category; Scfeguards

== Loca tion: Middletown, PA (Three Mile Island 1) __ . Type of Licensee: PWR (B&W) 871 Mwe . of Inspection: Special, Announced - ' Da.., of Inspection: June 11-12, 1975 - ' Daces of Previous Inspection: May 21-23, 1975 Reporting Inspector: ' [//[/6 ' - hpector Jacque r ctor Accompanying Inspectors: G f d ME - Lewis Narrow, Reactor. Inspector DATE , DATE ?

Other Accompanying Personnel: Nora DATE [[///7.j' Reviewed By: a a-R.

C.

Hay Senior Reactor Inspector ' DATE 1452 096 , , . 7910190 b b b

. h.- ~ r .. ( I

--- ,p SUMMARY OF FINDINGS ' r.. l6 Enforcement Action [] =- A.

Items of Noncompliance . i.

None ~ B.

Deviation: E None . Licensee Action on Previously Identified Enforcement Items Not inspected.

. Design Changes E"

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.. "B" Decay Heat Removal Cooler Valve Supports are being modified to decrease (:f.{ the unit area loading.

(Details, Paragraph 4) --. Unusual Occurrences ~ ' None - . rz Other Significant Findines ~ A.

Current Findines 1.

Unresolved Items a.

Sccondary System Safety Valve Exhaust Pipe Supports There is no evidence to indicate that the bearing plate '= gap does not increase beyond the.027" at power levels below 100%. (Details, Paragraph 3) . b.

Decay Heat River Water Pump ~ The evaluation report by the Architect-Engineer concerning the cause of failure of the concrete foundations of the Decay Heat River Water Pump is not yet available for review.

(Details, Paragraph 5) B.

Status of Previously Unresolved Items 1452 no7 ' ' Not inspected.

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- Management Intervicw

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. k-A management 2.sterview was held at the plant site on June 12, 1975.

.. ~ Persons Present y.::- Metropolitan Edison Company L.. - J. Colitz, Urit 1 Superintendent W. Cotter, liechanical Engineer h"* J. Herbein, Station Superintendent W. Potts, Site Quality Assurance h D. Shovlin, Supervisor of Maintenance L; m General Public Services Corporation J. Wright, Resident Civil Engineer

l ems Discussed _

.

i A.

Purpose of the Inspection The inspector stated that the purpose of the inspection was to review the Secondary System Safety Valve Exhaust Pipe problem, examine the ' repairs on the "B" Decay Heat Removal Cooler outlet valve supports

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and to review the repairs on the Decay Heat River Water Pump founda- _ tions.

(Details, Paragraph 2) B.

Secondary System Safety Valve Exhaust Pipe Supports ..1,.^ j The inspector discussed the apparent lack of evidence to prove that the bearing plate gap does not exceed.027 inch during power levels less than 100%. The licensee concurred that the bearing plate gaps could be greater at power levels less.than 100% and that measurements at lower power levels would be made.

(Details, Paragraph 3) T C.

Decay Heat Removal Cooler Valve Supports . - Se inspector discussed the progress of the repairs on the valve supports and the licensee stated the repairs would be completed .._.

within four (4) weeks.

(Details, Paragraph 4) 1452 098.

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t-3-r _ I t D.

Decav He,st River Water Pump [f.. .. - The inspector stated that inspection of the licensee's corrective {{ action rtlative to the pump foundation problem could not be completed g until the licensee's evaluation report is issued.

! L:. The licensee stated that the report would be available within sixty hi (60) days.

(Details, Paragraph 5) f The licensee acknowledged.the inspectors comments.

[22p t': . 1452 099 m . O . . e .. . . e e

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, ~ ) ! . DETAILS W-

i.. 1.

Persons Contacted .. p. '.. f+ Metropolitan Edi.* in Company L p.

J. Herbein, S.mrion Superintendent " J. Colitz, .nir 1 Superintendent . . R. Sucsers, P.oj ect Engineer, Mechanical I? W. Cotter, Mechanical Engineer I W. Potts, Site Quality Assurance D. Shovlin, Supervisor of Maintenance General Public Services Corporation J. Wright, Resident Civil Engineer

D 2.

Purpose of the Inspection

The purpose of the inspection was to: (a) Review the analysis of the Secondary System Safety Valve Exhaust Pipe Support bearing plate gap and to inspect the supports; (b) Examine the repair of ', the supports for valve DH-V-19B, outlet of "B" Decay Heat Removal i Cooler; and (c), Review the repairs to the Decay Hea't River Water e4 Pump (DR-P-1B) foundation.

3.

Secondary System Safety Valve Exhaust Pipe Supports The Three Mile Island, Unit 1 (TMI-1) experienced a gap between the bearing plates of the secondary system safety valve exhaust pipe supports (ref. Metropolitan Edison Company letter dated, April 2, 1975, Non-Routine Report 75-03).

• The inspector observed several of the bearing plate supports for a better understanding of the problem and then reviewed the engi-neering data and documentation that evaluated the condition and

- proposed the short and long term corrective action.

. The short term corrective action corsisted of making calculations . to determine the maximum allawable gap that could be tolerated between the bearing plates and then measuring this gap with a thickness gage at 100% power.

If the gap exceeded a predetermined distance it would be adjusted to within an acceptable distance.

The inspector, with the assiscance of the licensee's Plant Mechanical Engineer, could not ascertain if the calculations for maximum allow- ,

1452 100

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- 5- ' i )) able gap truly addressed the " worst case" condition.

It is con-

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ceivable that the actual maximum gap and greatest reaction force - felt by the piping could occur at some power level less than 100%,

the only point where measurements are being taken.

This item is d=- considered unresolved.

[= The long term corrective action consists of evaluating alternate means to replace the present bearing plata configuration.

4.

"B" Decay Heat Removal Cooler Valve Supports e The inspector observed the repairs being performed on valve suppo.rts for DH-V-19B, Outlet from Decay Heat Removal Cooler, "B".

The valve supports experienced cracking of the concrete footings under the valve support plates.

The valve supports consist of a symmetrical . array of six legs, radiating from the pipe adjacent to the valve, that terminate into load spreading plates that are bolted and grouted to the floor.

The cause of the failure in the grouting is believed to have been caused by: (a) the bolte being tightened excessively; (b) poor bonding of the grouting; and (c) the load plates being too small.

The repair consists of enlarging the bearing plates and properly grouting the, installation.

The inspector observed that only two x ) of the six larger bearing plates have been installed, without the trouting.

It was stated by the licensee that the installation would be completed within four (4) weeks.

5.

Decay Heat River Water Pump The licensee had reported (Ao 50-289/75-14) shearing of the motor shaf t of the Decay Heat River Water Pump (DR-P-1B) and cracking = ' of its concrete foundation.

Inspection o.f the remaining river water pump foundations by the licensee revealed similar cracks in the foundation of the Nuclear Services River Water Pump (NR-P-1A).

The inspector examined the cracked foundations, photographs of the DR-P-1B foundation taken with the sole plate removed, and base plate " hold down" clamps which had been installed to inchor the base plates of DR-P-1B and NR-P-1A to meet the original seismic - design criteria.

The inspector also observed work in progress on installation of thrust restraints for the river water pumps.

These restraints had been installed on six of the twelve river water pu=ps, including DR-P-1B and NR-P-1A.

Installation of restraints on the remaining six pumps was in progress.

1452 101 - _

. . ,, -6- , ..: In response to the inspector's question, the licensee stated that a report of the Architect-Engineer's evaluation of the cause of ..~ failure of the concrete in the foundations was in preparation and would be available within sixty (60) days.

This item is unresolved, n [:j [E.

' n . 1452 102 " r il @f 1;. bS.

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