ML20058F095
| ML20058F095 | |
| Person / Time | |
|---|---|
| Issue date: | 10/05/1990 |
| From: | Cline W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Haughney C NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| References | |
| NUDOCS 9011080087 | |
| Download: ML20058F095 (3) | |
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MEMORANDUM FOR:
C. Haughney, Chief Fuel Cycle Safety Branch l
Division of Industrial and Medical Nuclear Safety l
FROM:
William E. Cline, Chief Nuclear Materials Safety and Safeguards Branch Division of Radiation Safety and Safeguards l
SUBJECT:
TRANSMITTAL OF DRAFT INFORMATION NOTICE ON EXPL0SION OF AMMONIUM DlURINATE (ADU) PUMPS
.l This memorandum transmits for your information and possible use the i
subject' draft Information Notice. As a result of two events that could have-i 3
been life; threatening we feel this Notice may help negate possible existing safety problems at other facilities.
If you have any questions, please call me at FTS: 841-0346..
-l William E.-Cline-
Enclosure:
Draft Information Notice
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UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS WASHINGTON, D.C.
20555 NRC INFORMATION NOTICE NO. XX-XX: EXPLOSIONOFAMMONIUMDIURINATE(ADU) PUMP Addressees:
All Uranium Fuel Fabricatiti, and Conversion Facilities.
Purpose:
This Information Notice-is.being issued to alert uranium fuel fabrication and conversion. facilities 1;f an explosion potential associated with the pumping of' solution - containing a nmonium nitrate.
This explosion potential could also exist with the pumping of other solutions in which the chemical characteristics of the solute are simila r to t'iose of ammonium nitrate. as described below.. It is suggested-that recipients raview the information here and consider actions, if appropriate,.to. preclude possible pump explosion potential.
However, this information:does not constitute new U.S. Nuclear Regulatory. Commission (NRC)
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requirements, therefore no spec lfic action or written response-is required.
g; Description'of Circumstances:
On 12/7/88 er fuel. fabrication facility had an incident occur in which a pump servicing an uranyl nitrate system exploded; and on 4/29/90 inother fuel p
'fabricatica f acility experienced a' pump explosion associated wi.h an ammonium diurin;ie(ADU) system.: The following.was common to both incidents:
1.
The pumps - had been " dead headed" for a lengthy perk d of time (e.g. 43 hours4.976852e-4 days <br />0.0119 hours <br />7.109788e-5 weeks <br />1.63615e-5 months <br />) and this' overheated the pump causing the solutions within the pump and leaking back to the pump to concentrate, possibly to the point of having boiled dry.-
It had been determined that dryness -is not a;necessary condition for ammonium nitrate to-explode.-
A concentrated solution together with activation energy provided by-the overheated pump would'have been sufficient.
2.
The explosive substance was' determined to have been ammonium nitrate, both -. ammonium and nitrate ions having been part of the total dissolved material.
The " dead heading" of the' pump was caused by a closed valve in one case, and by the _ clogging of a flow restricting orifice with accumulated' solids in the other
' case.
The explosions have been formally characterized as a " rapid thermal decomposition," i.e; no ignition or detonation occurred. The pump housing had been-blown apart with Lufficient force to break the bolts which ' hold it i
together and, e.9, in one of the instances, send the suction half of the pump
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- off. as a projectile which struck a steel pipe, bending it 15 degrees, af ter which it skidded off for another 16 feet before coming to rest.
i In one of th'e instances one individual who was in the affected area received a minor laceration requiring first aid, No overexposures from the resulting p
uranium contamination occurred.
Dis Jssion:-
The events described in this Information Notice emphasize the.need for uranium processing; facilities to identify potentially explosive compounds and mixtures, i
be, aware.of where they are located or where they can accumulate or form, and take preventive measures to preclude the conditions which could cause an explosio'n to occur.
For-the indents discussed above, some of the corrective actions taken or s
considered consisted of the following:
Use a. temperature sensor shut-off device with pump.
a s.
t S-Implement strong administrative control (i.e.
independent Wa-
. verification sign-off) regarding correct valve position.
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Evaluate-other systems in the plant for similar potential, i.e.
L presence of, or potential for formation of ammonium nitrate, together with activation energy source,
,m' In automatic or semi-automatic operations,. use " dead-man" switches instead of normal manual switches to prevent personnel from overriding
' pump _' operations.
. Use a water rinse between two operations involving nitric acid and amonium hydroxide to preclude the formation of ammonium nitrate.
Evaluate vent and scrubber systems since a ~ multitude of materials-pass though them.--
Interlock pumps with. tank level indicators to shut pumps off on low
'1;. vel ;.
Remove unneccesary discharge valves to prevent ' dead-heading."
Implement valve tagging system.
This Information Notice does not require any written response to the-NRC.
I f-you have any questions about this_ matter, please contact the appropriate NRC Regional. office or this office.
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