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

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{{#Wiki_filter:UNITED STATES NUCLEAR REGULATORY
{{#Wiki_filter:UNITED STATES


COMMISSION
NUCLEAR REGULATORY COMMISSION


OFFICE OF INSPECTION
OFFICE OF INSPECTION AND ENFORCEMENT


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


Notice No. 79-07 RUPTURE OF RADWASTE TANKS Description
===RUPTURE OF RADWASTE TANKS===


of Circumstances:
==Description of Circumstances==
In November, 1977 a radwaste tank ruptured at the Millstone
:
                                                          Millstone Nuclear


Nuclear Power Station. Two problems led to the tank failure. First, the tank vent, which was intended to relieve excessive
In November, 1977 a radwaste tank ruptured at the               First, the tank


pressure in the radwaste tank, had been plugged by accumulated
Power Station. Two problems led      to the tank failure.


solidified
pressure in the radwaste


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


Second, corrosion
of  the  radwaste    tank to withstand


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


of the radwaste tank to withstand pressure.
tank   due


Individually, or in combination, these problems were causa-tive factors in the rupture of the radwaste tank due to overpressurization.
tive factors in the rupture of the radwaste


The Licensee Event Report states that an aerated waste concentrates
waste concentrates tank


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


and ruptured.
boric  acid  concentration.     These


The tank contained
rator concentrates with a 10-12 percent                  formed    a  solid


radwaste evapo-rator concentrates
concentrates, when cooled to ambient temperatures, entered the vent line


with a 10-12 percent boric acid concentration.
crystaline structure. Apparently, concentrate had            the tank so that a


These concentrates, when cooled to ambient temperatures, formed a solid crystaline
by previous tank overflows or purging of air through            eventually led to


structure.
buildup


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


had entered the vent line by previous tank overflows
a flow blockage in the vent line. The licensee, pressure to the tank.


or purging of air through the tank so that a solid buildup occurred in the vent line. This buildup eventually
out or clear a radwaste pipe, applied 100 PSI      air


led to a flow blockage in the vent line. The licensee, in an attempt to blow out 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 relieve pressure.
vent could not relieve


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


and ruptured.This tank had a history of corrosion
pressure. Therefore, the tank overpressurized


problems such that the corrosion probably caused some weakness which contributed
that the corrosion


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


of type 304 stainless
to


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


amounts of chlorides
were present in


were present in the aerated waste system and, consequently, in the waste concentrate
coast site such that significant amounts of chlorides


tank. The presence of significant
the waste concentrate


amounts of chlorides, coupled with residual welding stresses in the type 304 stainless
the aerated waste system and, consequently, in                    coupled with


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


Since radwaste tanks of this type are used at most power reactors, the potential
residual welding stresses in the type 304 stainless


may exist for similar events at other power reactors.
chloride stress corrosion.


Also, such events can be avoided by proper procedures
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
and periodic examination


o*(3 IE Information
such events can be avoided by proper procedures
 
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
o*(3*


radiation
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


exposure resulting from the repair and clean-up operations.
minimize the probability of such an event. Prevention of such events


No specific action or written response to this Information
will minimize, the possibility of personal injury, in-plant contamination, releases of radioactivity, and occupational radiation exposure resulting


Notice is required.
from the repair and clean-up operations.


If you require additional
No specific action or written response to this Information Notice is


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


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


this subject, contact the Director of the appropriate
ISSUED IN 1979 Information Subject                      Date      Issued To


NRC Regional Office.
===Notice No.                               Issued===
79-01      Bergen-Paterson Hydraulic    2/2/79    All power reactor


IE Information
Shock and Sway Arrestor                  facilities with an


Notice No. 79-07 March 26, 1979 LISTING OF IE INFORMATION
OL or a CP


===NOTICES ISSUED IN 1979 Information===
79-02       Attempted Extortion -         2/2/79     All Fuel Facilities
Notice No.Subject Date Issued 79-01 79-02 79-03 79-04 79-05 79-06 Bergen-Paterson


Hydraulic Shock and Sway Arrestor Attempted
Low Enriched Uranium


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


-Low Enriched Uranium Limitorque
Limit Switch Lubricant                  facilities with an


Valve Geared Limit Switch Lubricant Degradation
OL or a CP


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


Safety Features Use of Improper Materials in Safety-Related
Engineered                              facilities with an


Components
Safety Features                          OL or a CP


Stress Analysis of Safety-Related
79-05      Use of Improper Materials    3/21/79    All power reactor


Piping Rupture of Radwaste Tanks 2/2/79 2/2/79 2/9/79 Issued To All power reactor facilities
in Safety-Related Components            facilities with an


with an OL or a CP All Fuel Facilities
OL or CP


All power reactor facilities
79-06      Stress Analysis of            3/23/79    All Holders of


with an OL or a CP 2/16/79 All power reactor facilities
Safety-Related Piping                    Reactor OL or CP


with an OL or a CP 3/21/79 All power reactor facilities
79-07      Rupture of Radwaste Tanks    3/26/79   All power reactor


with an OL or CP 3/23/79 All Holders of Reactor OL or CP 3/26/79 All power reactor facilities
facilities with an


with an OL or CP 79-07 }}
OL or CP }}


{{Information notice-Nav}}
{{Information notice-Nav}}

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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