Information Notice 1979-07, Rupture of Radwaste Tanks: Difference between revisions

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{{#Wiki_filter:UNITED STATESNUCLEAR REGULATORY COMMISSIONOFFICE OF INSPECTION AND ENFORCEMENTWASHINGTON, D.C. 20555March 26, 1979IE Information Notice No. 79-07RUPTURE OF RADWASTE TANKS
{{#Wiki_filter:UNITED STATES
 
NUCLEAR REGULATORY COMMISSION
 
OFFICE OF INSPECTION AND ENFORCEMENT
 
WASHINGTON, D.C. 20555 March 26, 1979 IE Information Notice No. 79-07
 
===RUPTURE OF RADWASTE TANKS===


==Description of Circumstances==
==Description of Circumstances==
:In November, 1977 a radwaste tank ruptured at the Millstone NuclearPower Station. Two problems led to the tank failure. First, the tankvent, which was intended to relieve excessive pressure in the radwastetank, had been plugged by accumulated solidified concentrates. Second,corrosion had weakened the capability of the radwaste tank to withstandpressure. Individually, or in combination, these problems were causa-tive factors in the rupture of the radwaste tank due to overpressurization.The Licensee Event Report states that an aerated waste concentrates tankwas overpressurized and ruptured. The tank contained radwaste evapo-rator concentrates with a 10-12 percent boric acid concentration. Theseconcentrates, when cooled to ambient temperatures, formed a solidcrystaline structure. Apparently, concentrate had entered the vent lineby previous tank overflows or purging of air through the tank so that asolid buildup occurred in the vent line. This buildup eventually led toa flow blockage in the vent line. The licensee, in an attempt to blowout or clear a radwaste pipe, applied 100 PSI air pressure to the tank.The tank was designed for 15 PSI and the plugged vent could not relievepressure. Therefore, the tank overpressurized and ruptured.This tank had a history of corrosion problems such that the corrosionprobably caused some weakness which contributed to the rupture. Thetank was constructed of type 304 stainless steel. The plant was a sea-coast site such that significant amounts of chlorides were present inthe aerated waste system and, consequently, in the waste concentratetank. The presence of significant amounts of chlorides, coupled withresidual welding stresses in the type 304 stainless steel, resulted inchloride stress corrosion.Since radwaste tanks of this type are used at most power reactors, thepotential may exist for similar events at other power reactors. Also,such events can be avoided by proper procedures and periodic examinationo*(3 IE Information Notice No. 79-07 March 26, 1979 if personnel are aware of the problem. In addition, proper considera-tion of design features (e.g., materials selection and vent designs) canminimize the probability of such an event. Prevention of such eventswill minimize, the possibility of personal injury, in-plant contamination,releases of radioactivity, and occupational radiation exposure resultingfrom the repair and clean-up operations.No specific action or written response to this Information Notice isrequired. If you require additional information regarding this subject,contact the Director of the appropriate NRC Regional Office.
:
                                                          Millstone Nuclear
 
In November, 1977 a radwaste tank ruptured at the               First, the tank
 
Power Station. Two problems led     to the tank failure.
 
pressure in the radwaste
 
vent, which was intended to relieve excessive           concentrates. Second, tank, had been plugged by accumulated     solidified
 
of  the  radwaste    tank to withstand
 
corrosion had weakened the capability             these  problems    were causa- pressure. Individually, or in combination,                   to  overpressurization.
 
tank  due
 
tive factors in the rupture of the radwaste
 
waste concentrates tank
 
The Licensee Event Report states that an aerated               radwaste evapo- was overpressurized and ruptured. The       tank contained
 
boric  acid  concentration.      These
 
rator concentrates with a 10-12 percent                   formed    a  solid
 
concentrates, when cooled to ambient temperatures, entered the vent line
 
crystaline structure. Apparently, concentrate had           the tank so that a
 
by previous tank overflows or purging of air through             eventually led to
 
buildup
 
solid buildup occurred in the vent line. This           in  an  attempt to blow
 
a flow blockage in the vent line. The licensee, pressure to the tank.
 
out or clear a radwaste pipe, applied 100 PSI       air
 
vent could not relieve
 
The tank was designed for 15 PSI and the pluggedand ruptured.
 
pressure. Therefore, the tank overpressurized
 
that the corrosion
 
This tank had a history of corrosion problems such the rupture. The
 
to
 
probably caused some weakness which contributed           The plant was a sea- tank was constructed of type 304 stainless   steel.
 
were present in
 
coast site such that significant amounts of chlorides
 
the waste concentrate
 
the aerated waste system and, consequently, in                     coupled with
 
tank. The presence of significant amounts of chlorides,     steel, resulted in
 
residual welding stresses in the type 304 stainless
 
chloride stress corrosion.
 
power reactors, the
 
Since radwaste tanks of this type are used at most     power reactors. Also, potential may exist for similar events at other
 
and periodic examination
 
such events can be avoided by proper procedures
 
o*(3*
 
IE Information Notice No. 79-07                           March 26, 1979 if personnel are aware of the problem. In addition, proper considera- tion of design features (e.g., materials selection and vent designs) can
 
minimize the probability of such an event. Prevention of such events
 
will minimize, the possibility of personal injury, in-plant contamination, releases of radioactivity, and occupational radiation exposure resulting
 
from the repair and clean-up operations.
 
No specific action or written response to this Information Notice is
 
required. If you require additional information regarding this subject, contact the Director of the appropriate NRC Regional Office.
 
IE Information Notice No. 79-07 March 26, 1979 LISTING OF IE INFORMATION NOTICES
 
ISSUED IN 1979 Information Subject                      Date      Issued To
 
===Notice No.                                Issued===
79-01      Bergen-Paterson Hydraulic    2/2/79    All power reactor
 
Shock and Sway Arrestor                  facilities with an
 
OL or a CP
 
79-02      Attempted Extortion -        2/2/79    All Fuel Facilities
 
Low Enriched Uranium
 
79-03      Limitorque Valve Geared      2/9/79    All power reactor
 
Limit Switch Lubricant                  facilities with an
 
OL or a CP
 
79-04      Degradation of                2/16/79    All power reactor
 
Engineered                              facilities with an
 
Safety Features                          OL or a CP
 
79-05      Use of Improper Materials    3/21/79    All power reactor
 
in Safety-Related Components            facilities with an
 
OL or CP
 
79-06      Stress Analysis of            3/23/79    All Holders of
 
Safety-Related Piping                    Reactor OL or CP
 
79-07      Rupture of Radwaste Tanks    3/26/79    All power reactor
 
facilities with an


IE Information Notice No. 79-07March 26, 1979LISTING OF IE INFORMATION NOTICESISSUED IN 1979InformationNotice No.SubjectDateIssued79-0179-0279-0379-0479-0579-06Bergen-Paterson HydraulicShock and Sway ArrestorAttempted Extortion -Low Enriched UraniumLimitorque Valve GearedLimit Switch LubricantDegradation ofEngineeredSafety FeaturesUse of Improper Materialsin Safety-Related ComponentsStress Analysis ofSafety-Related PipingRupture of Radwaste Tanks2/2/792/2/792/9/79Issued ToAll power reactorfacilities with anOL or a CPAll Fuel FacilitiesAll power reactorfacilities with anOL or a CP2/16/79 All power reactorfacilities with anOL or a CP3/21/79 All power reactorfacilities with anOL or CP3/23/79 All Holders ofReactor OL or CP3/26/79 All power reactorfacilities with anOL or CP79-07 }}
OL or CP }}


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Latest revision as of 03:41, 24 November 2019

Rupture of Radwaste Tanks
ML031180125
Person / Time
Site: Waterford, 05000000
Issue date: 03/26/1979
From:
NRC/IE
To:
References
IN-79-007, NUDOCS 7904120337
Download: ML031180125 (3)
v • d • e


UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF INSPECTION AND ENFORCEMENT

WASHINGTON, D.C. 20555 March 26, 1979 IE Information Notice No. 79-07

RUPTURE OF RADWASTE TANKS

Description of Circumstances

Millstone Nuclear

In November, 1977 a radwaste tank ruptured at the First, the tank

Power Station. Two problems led to the tank failure.

pressure in the radwaste

vent, which was intended to relieve excessive concentrates. Second, tank, had been plugged by accumulated solidified

of the radwaste tank to withstand

corrosion had weakened the capability these problems were causa- pressure. Individually, or in combination, to overpressurization.

tank due

tive factors in the rupture of the radwaste

waste concentrates tank

The Licensee Event Report states that an aerated radwaste evapo- was overpressurized and ruptured. The tank contained

boric acid concentration. These

rator concentrates with a 10-12 percent formed a solid

concentrates, when cooled to ambient temperatures, entered the vent line

crystaline structure. Apparently, concentrate had the tank so that a

by previous tank overflows or purging of air through eventually led to

buildup

solid buildup occurred in the vent line. This in an attempt to blow

a flow blockage in the vent line. The licensee, pressure to the tank.

out or clear a radwaste pipe, applied 100 PSI air

vent could not relieve

The tank was designed for 15 PSI and the pluggedand ruptured.

pressure. Therefore, the tank overpressurized

that the corrosion

This tank had a history of corrosion problems such the rupture. The

to

probably caused some weakness which contributed The plant was a sea- tank was constructed of type 304 stainless steel.

were present in

coast site such that significant amounts of chlorides

the waste concentrate

the aerated waste system and, consequently, in coupled with

tank. The presence of significant amounts of chlorides, steel, resulted in

residual welding stresses in the type 304 stainless

chloride stress corrosion.

power reactors, the

Since radwaste tanks of this type are used at most power reactors. Also, potential may exist for similar events at other

and periodic examination

such events can be avoided by proper procedures

o*(3*

IE Information Notice No. 79-07 March 26, 1979 if personnel are aware of the problem. In addition, proper considera- tion of design features (e.g., materials selection and vent designs) can

minimize the probability of such an event. Prevention of such events

will minimize, the possibility of personal injury, in-plant contamination, releases of radioactivity, and occupational radiation exposure resulting

from the repair and clean-up operations.

No specific action or written response to this Information Notice is

required. If you require additional information regarding this subject, contact the Director of the appropriate NRC Regional Office.

IE Information Notice No. 79-07 March 26, 1979 LISTING OF IE INFORMATION NOTICES

ISSUED IN 1979 Information Subject Date Issued To

Notice No. Issued

79-01 Bergen-Paterson Hydraulic 2/2/79 All power reactor

Shock and Sway Arrestor facilities with an

OL or a CP

79-02 Attempted Extortion - 2/2/79 All Fuel Facilities

Low Enriched Uranium

79-03 Limitorque Valve Geared 2/9/79 All power reactor

Limit Switch Lubricant facilities with an

OL or a CP

79-04 Degradation of 2/16/79 All power reactor

Engineered facilities with an

Safety Features OL or a CP

79-05 Use of Improper Materials 3/21/79 All power reactor

in Safety-Related Components facilities with an

OL or CP

79-06 Stress Analysis of 3/23/79 All Holders of

Safety-Related Piping Reactor OL or CP

79-07 Rupture of Radwaste Tanks 3/26/79 All power reactor

facilities with an

OL or CP


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