ML19338D518
| ML19338D518 | |
| Person / Time | |
|---|---|
| Site: | 05000152 |
| Issue date: | 08/21/1980 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Ziemer P PURDUE UNIV., WEST LAFAYETTE, IN |
| References | |
| NUDOCS 8009230387 | |
| Download: ML19338D518 (4) | |
Text
-
.e
=,
/pe %g't(
~
- 4-UNITED STATES
- 8 ',,., (
NUCLEAR ' REGULATORY COMMISSION PDR' o
t"
. -3
- nEoion sii
.'/
m nooseveu nor.o sf..vf*
.g.
3 aun eu.vu. n.unois som AUS -2 f $80 Docket No. 50-152 Purdue University ATTN:
Dr. Paul L.JZiemer
-Radiological Control Officer Bionucleonics Department
-West *afayette, IN 47907 Gentlemen:
The enclosed IE Circular No. 80-20 is forwarded for your information.
If'there are any questions related to the suggested actions, please contact this office.
Sincerely, t$ko.b Y.N(d ~
/w 0 James G. Keppler Director
Enclosure:
IE Circular
-No. 80-20 t
cc w/ encl:
Central Files ~
m u s
=3
-SSINS:
6830:
Accession No.:
'8006190036.
~
-IEC 80-20 UNITED STATES NUCLEAR REGULATORY COMMISSION I
0FFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 f
gffT August 21, 1980
.ht
,g IE Circular No. 80-20:
CHANGES!IN SAFE-SLAB TANK DIMENSIONS
- Description of Circumstances:
During 'a routine inspection at' a fuel facility, an NRC inspector received a report of significant dimensional changes in safe geometry tanks. The tanks were used to store. low enriched uranium solutions from a scrap dissolver. The problem was first identified when a sight glass mounted on the large face of
. one of three' safe-slab tanks cracked from the strain of tank dimensional changes.
Further investigation and measurements revealed that the large faces of two of the tanks had bulged and increased the thickness dimensions of the tanks.
The maximum bulge occurred at the center of one of the tanks, increasing the-
. tank thickness 2 1/2 in. beyond the design thickness of 5 1/2 in. The bulge tapered from the tank centers to the designed 5 1/2=in. at the tank edges.
The tanks were made of 1/8-in. type 304 stainless steel with the tank edges and large faces supported and stiffened by 3/16-in. angle iron.
The cause of the bulging was believed to be overpressurization due to partial plugging of the. tank vent liaes.
Contributing factors may have been excessive transfer rates, metal fatigue aggravated by corrosion, and the high specific gravity of the stored solution.
Replacement tanks were provided with tie-bars and heavier 1/4-in. angle iron stiffeners to preserve the thickness dimensions.
Conservative calculations, taking>into account the weight of solution, tank dimensions, and tie-bar and stiffener strength, indicated that required dimensions would be maintained. A precondition for the calculations required that the tank vent system be designed to prevent accidental pressurization.
To prevent accidental pressurization, a 1-1/2-in. overflow line was connected to the 1-1/2-in.. vent line to the process offgas (P0G) system at a point immediately
- ve each tank.
This provided a positive overflow as well as a 1
second vent in case a plug occurred in the main P0G line.
Additionally, each tank was provided with a 2" x 4" inspection port at the top with a cover free to " float" should pressurization occur.
The tank dimensions were approximately 62" x 62" x 5 1/2".
The tank locations were parallel ~to and about 1 ft removed from the scrap recovery area walls.
The' visual detection of the 2-1/2-in. deflection of the large tank face from a point in front of.the tank is usuaily c'ifficult so that measurements should be
- made with calipers or similar equipment to assure detection of significant distortien.
i a
g
. g-IEC 80-20 August-21, 1980-Pags 2 of 2 Notice to l'icensees:
All' licensees.using safe-slab tanks should be aware of the possible changes in tank ~ dimensions resulting from hydraulic or pneumatic forces.
Certain steps should be taken to prevent or detect changes in safe-slab tank. dimensions.
.These actions include the'following:
(1) Structural analyses shbuld be reviewed for all vessels designed to be geometrically safe to assure that the possibility of pressurization has been adequately considered. 'The.use of tie-bars and rigid steel supports should be considered in designs for naw tanks.
-(2) The possibility of. vent lines becoming plugged should be studied and special overflow. mechanisms.should be provided if pressurization by vent
'line plugging is possible.'
C
(3) -Provision should be made for routine dimensional checks of geometrically safe vessels. These checks.should be made whether or not the vessels are subject to pressurization.
Jh) written response to this circular'is required.
If additional information regarding this subject is required, contact the Director of this office.
an e
h e
I o
c
~
T e;,. n
='
-A e
s s
c.
E o'
,IEC 80-20
' - f *r
' August 21, 1980' 3.
'4
- ~
RECENTLY~ ISSUED' IE. CIRCULARS
. Circular
~ No.
Dateiof Subject-
' Issue Issued to s
_80-19, Noncomplia'nce with 8/26/80 All-medical'licen' sees
' License ! Requireme~nts ; for
'~
- Medical-Licensees 80-18' 10 CFR 50.59 Safety.
8/22/80-LAll power reactor.
1 Evaluations for Changes :to-
. facilities with an
-Fuel-Pin Damage Due to Water 17/23/80-All' holders of PWR' Jet from BaffleL Plate Corner-OLs and PWR cps-80-16.
Operational-Deficiencies-In 6/27/80.
~All power reactore Rosemount Modek 51000 Trip.
facilities with an Units And Model 1152 Pressure OL or a CP Transmitters-80-15 Loss of' Reactor. Coolant Pump 6/20/80 All power reactor Cooling and' Natural Circula-
-facilities with an
' tion Cooldown~
-RadioactiveLContamination of 6/24/80 All holders of power Plant Demineralized Water and research= reactor System and. Resultant Internal licenses (operating Contamination of Personnel
'and construction permits), and fuel cycle' licensees80-13L 1 Grid Strap Damage:in
~
~'5/18/80 ~
All holder's of reactor Westinghouse'Fue11 Assemblies OLstand cps80-121 Valve-Shaft-To-Actuator Key 5/14/80-All holders of reactor-a May Fall Out'of Place When-OLs and' cps Mounted Below Horizontal Axis
' l
- 1 80-11 Emergency Diesel Generator.
5/13/80 '
All holders of a power
' I
- Environmental Qualification OLs and cps offEquipment ' 09
' Problems'With Plant Internal 4/28/80 All holders.of a power
~ Communications Systems-reactor OL or CP v
~.