ML20216F312
| ML20216F312 | |
| Person / Time | |
|---|---|
| Site: | Waltz Mill |
| Issue date: | 05/27/1960 |
| From: | Mann M US ATOMIC ENERGY COMMISSION (AEC) |
| To: | Nelson C US ATOMIC ENERGY COMMISSION (AEC) |
| Shared Package | |
| ML20216F225 | List:
|
| References | |
| FOIA-98-100 NUDOCS 9804170027 | |
| Download: ML20216F312 (3) | |
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Curtis A. Nels on, Dire ctor Divisies of Inspecties 3
Marvin M. Mama, Chairman gg%
Investigating Committee INVESTIGATION OF RADL1 TION INCIDENT AT THE WESTINGHO USE TESTING REACTOR, LICENSE TR-2, WALTZ MILL, PENNSYLVANL^.
Symbol: INS:MMM Transmitted herewith is the report of investigation af the subject incident.
This incident resulted in partial destruction of one reactor fuel element through overheating and subsequent melting.
The techni-cal origin of the incident is not yet known, but it is likely that either or both of two factors played a major role: (1) inadequate coolant flow under conditions existing at the time, (2) defective metallurgical banding in the fuel element.
No personnel overexposures occurred and no offsite contamination was found.
However, this incident, but for a fortunate circumstance, could have been rather more serions.
The elensent wMeh failed was now, and having been irradiated for only two days at higla power, its fission predact content was relatively low.
The WTR erganisation functioned effectively la coping with the aftereffects of the incident.
Evacuation of the facility, necessitated by the gammaa radiaties emanating from the process water head tank, was effected +E, :S*ionely, and radiation surveys of the surrounding territory were imetituted preasytty.
Perosas in the saan11 settlessents a fore smiles away were alerted on the ehmace that detectable airborne radiaties maight obtain teasperarily la these areas.
It appears that the public relations facter worked est favorably.
Renneval of the reacter core, including the damaged fuel, and decentamination of the reactor has proceeded without incident.
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l Curtis A. Nelson In addition u the technical factors mentioned ab ove in connection with the incident, certain features of the WTR organimation appear to have played important roles.
It is a matter of record that the h TR Safeguards Committee had reviewed the series af experiments being conducted to study the onset of boiling in the WTR, and as a consequence, to set certain teshmical standards for normal operation.
A was during one of these experiments that the incident escurred.
The WTR Safeguards Camrrdttee had written technical speelfications and operational linaits for the tests, but ne detaRed written operating precedures had been provided.
For the test run on the date of the incident a specification had been prepared by the Chairman of the Safeguards Committee.
The full committee did not review this test, although Row, tempe rature, and power limits differed from those specified for previous tests.
Furthermore, possible abnormal situations had not been fully considered, and no written operating procedures for handling thereof had been provided.
While a number of individuals in the WTR organisaties are knowledge-able and experienced in remeter technology and operation, the reactor supervisor en duty during the incident had had only three months' experience.
The committee interviewed this man, and found that his understanding of reacter operatten was severely limited.
This,
coupled with the lack of detailed operating procedure for the test, constituted a substandard situation, leaving the operation, in our opinion, effectively unsupervised.
While WTR managsasent was present daring de test, ne spoeial naeasures were taisen to offset the defieleasy in sapervision.
The results of this estanties were that the rapid and speataneous decrease in power
- was not recognised as abnormal, and the esperviser apparently tastructed the operator to recover speetfied power, a move inconsisteet with safety of operation.
l While Westinghouse peroommel are studying the possible causes of the incident, the conapany has not fornaally ceavened a group to j
(continued)
- lt is our tentative opittion that the power decrease signalled the omer,,
beginning i Me ~iricidosi,~asd~that~iWfollowtig1Lan6ase 1n poweri- -
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_ directed aithdrawal of _ control rs4_merely ag.gravated
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O Curtis A. Nelson m -. e u, investigate all aspects of the incident, nor does it appear that the roles of management, organization and procedure have been objectively considered by the company.
Since the committee's visit to the h TR facility, experts in heat transfer phenomena at ORNL and at Westinghouse have made cal-culations on the basis of reactor conditions presumed to have existed at the time of the incident. Metallurgical studies of the damaged element are under way.
The committee believes that the heat transfer studies do not ex-clude the possibility that the phenomenon of " flow disease" caused the incident. It appears that until metallurgical studies of the damaged element are completed, it will not be possible to assess the probable cause of the incident.
The Division of Inspection continues to follow the studies mentioned and will report results as they become available.
Finally, this incident has raised an interesting question in regard to the philosophy of the design of the WTR. This reactor has been provided with a containment building, ostensibly for the purpose of aetaining therein such radioactivity as might be released from the reactor as the result of incidents such as, but not restricted to, the subject incident. As a matter of fact, the provision of a venting system for the process water head tank and for the process water surge tank, in the view of the committee, substantially negates the purpose and efficacy of the containment building. While the committee recognises that this feature of the design was duly approved via the licensing process, it is believed that such features deserve further conside ration.
It is recommended that the licensee be required to report to the Commis sion:
1.
A detailed account of the incident.
2.
Results of technical and managerial studies of the incident and its implications.
3.
Steps taken or planned in regard to equipment, organisation, and procedure to prevent recurrence of the incident.
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