ML20086F161

From kanterella
Jump to navigation Jump to search
Forwards Significant Deficiency Rept 2 Re Discovery of Cracks in Plate Girders Located in Reactor Bldgs.Initially Reported on 761209.Hold Placed on Const Activities That May Impose Substantial Addl Loads.Final Rept by 770401
ML20086F161
Person / Time
Site: Peach Bottom, Limerick, 05000000
Issue date: 01/11/1977
From: Boyer V
PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To: Volgenau E
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
Shared Package
ML20086F058 List:
References
10CFR-050.55E, 10CFR-50.55E, 2, NUDOCS 8312130086
Download: ML20086F161 (3)
v • d • e


Text

-_.--.___.,,,-._----_-_--__-----

PHILA LPHIA ELECTRIC COMP 2301 MARKET STREET PHILADELPHI A. PA.19101

~

b V.S.DOYER '

v6cs ratsiotiev January 11, 1977 Dr. Ernst Volgenau, Director Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, D.C. 20545

Subject:

Significant Deficiency Report Structural Steel Girder Cracks Limerick Generating Station-Units 1 & 2 NRC Construction Permit Nos. CPP3-106, 107 Referer.ce: Telecon of December 9, 1976 -

PECO (H.B. Winitsky) to USNRC-Region I (A. Toth)

File: QUAL 2-10-2, SDR #2

Dear Dr. Volgenau:

In compliance with 10CFR50.55, paragraph (c), we are submitting the attached interin Significant Deficiency Report concerning the discovery of cracks in plate girders located in the Unit I and 2 reactor buildings.

This occurrence was reported to the USNRC by the ref-crenced telecon.

We expect to submit our next and final report on this incident by April 1, 1977.

Sincerely, V. S. Boyer ,

GJR/cmr Attachment J. P. O'Reilly, Regional Directorate, USNRC, R2gTo$.,$IS , ... m " ' 97 F.' '

cc:

.g.

, jy;;'113 i -

, s ; \ \13 L\ t?,T LLS 8312130086 771005 PDR ADOCK 05000277 , 03ME, S PDR 9

s a

h Sinnificant Deficiency Recort - SDR No. 2 7.[,f ,jyf '

. :. . S w  % . ;p _ e_9..

Structural Steel Girder Defects i m/ X:g(.

Construction Permit Nos. CFPR-106 and CPPR-107 ~

, f.e.' 2*h.?

3-' -

? 4A

%. "$?'= y%' .

, ; ~,* -

DESCRIPTION OF DEFICIEUCY

1. -Q F ? E

~

Y

a. "#

v y On November 30, 1976 during the erection of structura' steel, a vertical s 1.% . 4 4 "Q

_3:

crack approximately 12 inches long was discovered in the web of a welded plate girder at Elevation 253'-0" in Reactor Building 2. Subsequent d.X[s L %.' W.L visual and nondestructive examinations made prior to Zecember 29, 1976 have indicated that a total of 24 plate girders of air.ilar configuration f$tt

' in Reactor Buildings 1 & 2 as well as the Radwaste Building have similar T;Mp defects ranging in length frca 1/2" to 3". The defoe .s have occurred only in the plate girder webs at the re-entrant corne: where the flange }Q;_W* i$Q.g o% 5 terminates and the web continues. Further visual and nondestructive fit.$.M[

examination of girders having similar end details is continuing. [ -4. '

CURRENT ACTION e.'W' ?}[.  :

II'.ksh-gj

1. A hold has been placed on certain construction cetivities that may impose substantial additional loads on affected . structures.
  • %/*pyj/y;?.?

4.";V.S?

y l,

2. 4A a., .3%7 3*'

All suspect girders are being inspected by nondcatructive procedures to determine whether defects exist.

i.h'f.N',l '

-% : r I'

!-@. m:4 3 es u Holes have been drilled at all known defects in order to avoid .JA < ; ,Q propagation of defects.

. g. .g ,7

- 4. An analysis is being done to determine the extent that construction o.~.m. #,4

.Mir. d-can continue until the girders have been repairci.

. 'g '.h 5 All suspect plate girders will be exposed for ir. pection. The safety p'tr*' ^

i.

of the structure will be assured by repairs to ::e girder or by an ,0. : 1 alternate method that recognizes the existence ef a defect. } jg {77.gi

]: 6. A sampling of rolled sections havin'g similar end details is being made to determine if similar defects exist. k. mMQ S.3 Tdr 9 9

7. An investigation to determine the cause(s) of th e defects is presently [(h7?[W underway. Concurrently, a procedure for repair; to the girders is being , b ii. .V 'O prepared. Af ter completion of the procedures, ...e repair program will

, be implemented. ?3a g.Q.

1. 2 b M w:+. p. -. :.

i a  % gh i .: u' ; -

ex wy y

-t

, .s . .s.

2 N l$.?

SDR-2 N

-z= -- J 3 .

%,.. .,,..:- + gg g-5 #

'I b - *

,e

o . .

O O SAFETY IMPLICATIdNS The results of engineering studies and inspections performed to date indicate that most construction-activities may safely proceed. After the completion of the tepair program, the structural integrity of the girders will be restored so that

~ the structure vill be capable of withstanding the design loading.

A final report will be issued when the investigation of the deficiency is completed. The report will provide information on the causes of the defects and the corrective action used to repair the defects.

e t

SDR-2 ,

e .

Retrieved from "https://kanterella.com/w/index.php?title=ML20086F161&oldid=2735411"