Category:NRC Information Notice[Table view]The following query condition could not be considered due to this wiki's restrictions on query size or depth: <code> [[:Beaver Valley]] OR [[:Millstone]] OR [[:Hatch]] OR [[:Monticello]] OR [[:Calvert Cliffs]] OR [[:Dresden]] OR [[:Davis Besse]] OR [[:Peach Bottom]] OR [[:Browns Ferry]] OR [[:Salem]] OR [[:Oconee]] OR [[:Mcguire]] OR [[:Nine Mile Point]] OR [[:Palisades]] OR [[:Palo Verde]] OR [[:Perry]] OR [[:Indian Point]] OR [[:Fermi]] OR [[:Kewaunee]] OR [[:Catawba]] OR [[:Harris]] OR [[:Wolf Creek]] OR [[:Saint Lucie]] OR [[:Point Beach]] OR [[:Oyster Creek]] OR [[:Watts Bar]] OR [[:Hope Creek]] OR [[:Grand Gulf]] OR [[:Cooper]] OR [[:Sequoyah]] OR [[:Byron]] OR [[:Pilgrim]] OR [[:Arkansas Nuclear]] OR [[:Braidwood]] OR [[:Susquehanna]] OR [[:Summer]] OR [[:Prairie Island]] OR [[:Columbia]] OR [[:Seabrook]] OR [[:Brunswick]] OR [[:Surry]] OR [[:Limerick]] OR [[:North Anna]] OR [[:Turkey Point]] OR [[:River Bend]] OR [[:Vermont Yankee]] OR [[:Crystal River]] OR [[:Haddam Neck]] OR [[:Ginna]] OR [[:Diablo Canyon]] OR [[:Callaway]] OR [[:Vogtle]] OR [[:Waterford]] OR [[:Duane Arnold]] OR [[:Farley]] OR [[:Robinson]] OR [[:Clinton]] OR [[:South Texas]] OR [[:San Onofre]] OR [[:Cook]] OR [[:Comanche Peak]] OR [[:Yankee Rowe]] OR [[:Maine Yankee]] OR [[:Quad Cities]] OR [[:Humboldt Bay]] OR [[:La Crosse]] OR [[:Big Rock Point]] OR [[:Rancho Seco]] OR [[:Zion]] OR [[:Midland]] OR [[:Bellefonte]] OR [[:Fort Calhoun]] OR [[:FitzPatrick]] OR [[:McGuire]] OR [[:LaSalle]] OR [[:Fort Saint Vrain]] OR [[:Shoreham]] OR [[:Satsop]] OR [[:Trojan]] OR [[:Atlantic Nuclear Power Plant]] OR [[:Crane]] </code>.
All holders of operating licenses for nuclear power reactors and all registered
users of NRC approved waste shipping packages.
Purpose
This information notice is intended to-alert addressees to a possible safety
problem resulting from incomplete draining and drying of shipping casks. It is
expected that recipients will review the information for applicability to their
facilities and consider actions, as appropriate, to avoid similar problems.
However, suggestions contained in this information notice do not constitute NRC
requirements; therefore, no specific action or written response is required.
Description of Circumstances
On May 9, 1990, a Chem-Nuclear System (CNSI) operator opened a Transnuclear, TN-RAM shipping cask (USA/9233/B(U)) containing approximately 16,000 curies of
waste-irradiated hardware (sheared control rod blades and local power range
monitors) at the Low-Level Radioactive Waste Disposal Site operated by CNSI at
Barnwell, South Carolina. The irradiated hardware was to'be placed in the
Class C waste trench. When the CNSI operator opened the shipping cask, approx- imately 75 gallons of water, having a near contact dose rate of 5 mr/hr, spilled from the cask, contaminating the off-loading equipment and the sur- rounding ground area.
CNSI personnel immediately closed the cask, removed it
from the trench area, and placed it in a secure parking area within the burial
site.
Subsequently, when the cask was completely dewatered at the waste
facility, an additional 121 gallons of contaminated water was removed from the
cask. The total volume of water found in this event was approximately 40
percent of the total cask volume.
Discussion:
The shipment originated at
irradiated hardware was in
pool.
The waste liner and
Millstone Nuclear Power Station, Unit 1. The
a waste liner which was stored in the spent fuel
cask were to be drained and dried before shipment.
The main cause of this event was an inadequate procedure used for draining and
drying the cask and liner.
This procedure failed to incorporate any method for
quantifying the amount of water drained from the cask. Additionally, this
procedure failed to specify an accurate reference value for the pressure of the
A
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IN 90-66 October 25, 1990 cask cavity with which to conduct the "dryness verification" test. The proce- dure specified that the test be conducted.at any, pressure above a "minimum"
pressure of 10 mbar, while the safety analysis report (SAR) called for the test
to be conducted at a pressure of 10 mbar (+2, -0 mbar). As a result,'the test:
was actually conducted at 27 mbar, which was the vapor pressure for water at.
..
the ambient temperature. Because the pressure in the cask cavity was not
sufficiently below the vapor pressure of water, the test results were incorrectly
interpreted, which allowed water to remain undetected in the cask..
Since this event the license holder has corrected these deficiencies in the
test procedure. The revised test procedure requires.that the water.drained
from the cask be quantified and compared to the volume of the container and
that the dryness test be consistent with the SAR by specifying that the dryness
test be performed at 10 mbar (+2, -0 mbar).
This information notice requires no specific action or written response. If
you have any.questions about the information in this notice, please contact one
of the technical contacts listed below or the appropriate NRC project manager.
IN 90-66 October 25, 1990 cask cavity with which to conduct the "dryness verification" test. The proce- dure specified that the test be conducted at any pressure above a "minimum"
pressure of 10 mbar, while the safety analysis report (SAR) called for the test
to be conducted at a pressure of 10 mbar (+2, -0 mbar).
As a result, the test
was actually conducted at 27 mbar, which was the vapor pressure for water at
the ambient temperature.
Because the pressure in the cask cavity was not
sufficiently below the vapor pressure of water, the test results were incorrectly
interpreted, which allowed water to remain undetected in the cask.
Since this event the license holder has corrected these deficiencies in the
test procedure.
The revised test procedure requires that the water drained
from the cask be quantified and compared to the volume of the container and
that the dryness test be consistent with the SAR by specifying that the dryness
test be performed at 10 mbar (+2, -0 mbar).
This information notice requires no specific action or written response. If
you have any questions about the information in this notice, please contact one
of the technical contacts listed below or the appropriate NRC project manager.
