ML20155A019

Insp Rept 70-1113/86-03 on 860218-21.No Violations or Deviations Noted.Major Areas Inspected:Followup on Conversion Reactor Event,Nuclear Criticality Safety, Operations Review & Procedures Re UF6 Cylinders

ML20155A019
Person / Time
Site:	07001113
Issue date:	03/31/1986
From:	Kahle T, Mcalpine E NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:
Shared Package
ML20155A000	List: ML20154S841 ML20155A019
References
70-1113-86-03, 70-1113-86-3, NUDOCS 8604080184
Download: ML20155A019 (7)

Text

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• >2 raro UNITED STATES o NUCLEAR REGULATORY COMMISSION y"- - ' ' ,'n REGION il g ,j 101 MARIETTA STREET. N.W.

• ATL ANT A. GEORGI A 30??3

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/ MAR 31 1986 Report No.: 70-1113/86-03 Licensee: General Electric Company Wilmington, NC 28401 Docket No.: 70-1113 License No.: SNM-1097 Facility Name: General Electric Company Inspection Conducted: February 18-21, 1986 Inspector: u3Yt_[] s '

3b /R Ohte Signed J. B. K $1~e

.\pproved by: El C Skm E. J. McAlpine, Section Chieh o 3/31[@6 Date Signed Division of Radiation Safety and Safeguards

SUMMARY

Scope: This routine, unannounced inspection involved 32 inspector-hours on site in the areas of followup on the conversion reactor event, nuclear criticality safety, operations review, and procedures pertaining to weighing and loading of UF6 cylinders.

Results: No violations or deviations were identified.

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REPORT DETAILS

1. Persons Contacted Licensee Employees

• B. F. Bentley, Acting Manager, Manufacturing

• A. G. Dada, Acting Manager, MT & E0

• R. Downing, Manager, Fabrication Manufacturing Engineering

• C. M. Vaughan, Acting Manager, Quality Assurance

• M. L. Faris, Manager, Major Projects

• D. L. Pensinger, Manager, Chemet Lab

• W. C. Peters, Manager, Nuclear Safety Engineering

• C. Schiltz, Manager, Components and Fuel Fabrication Engineering

• T. P. Winslow, Manager, Licensing and Nuclear Materials Management

• R. C. Pace, Manager, Powder Production Unit

• R. L. Torres, Manager, Radiation Protection

• B. S. Dunn, Specialist, Licensing Support

• R. H. D. Foleck, Senior Specialist Licensing Engineering

• B. J. Beane, Senior Engineer

• S. P. Murray, Senior Nuclear Safety Engineer R. Greer, Engineer M. Moser, Process Engineer R. Lewis, Supervisor, Radiation Protection J. Taylor, Senior Nuclear Safety Engineer H. Webb, Senior Nuclear Safety Engineer R. J. Keenan, Nuclear Safety Engineer P. E. Hann, Supervisor, Chemet Laboratory R. Owens, Supervisor, Shop Operations D. Teachey, Operator L. Divins, Manager, Chemical Process Engineering J. Wetzel, Manufacturing Engineer B. Brinkley, Supervisor, Shop Operations The inspector also interviewed several other licensee personnel.

• Attended exit interview

2. Exit Interview The inspection scope and findings were summarized on February 21, 1986, with those persons indicated in paragraph 1 above. Licensee representatives were informed that failure of the licensee to immediately notify Region II of the loss of material via the stack as a result of the GECO conversion reactor event would be an " unresolved item" until NRC decided if the unplanned release of the material was applicable to the 10 CFR 70.52(a) regulations.

See paragraph 3.

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The inspector acknowledged that most of the information provided to the inspector regarding the GECO process and equipment was company proprietary information and stated that efforts would be made to discuss details of the event and the licensee's corrective action without revealing company proprietary information in the inspection report.

3. Unresolved Items

• 10 CFR_70.52(a) states that each licensee shall report immediately to the appropriate NRC Regional Office by telephone and telegraph, mailgram, or facsimile any loss, other than normal operating loss, of special nuclear material. On January 22, 1986, as a result of a failure in the GECO conversion reactor process system, approximately 800 grams of 3.95 percent enriched uraniun were discharged to the envirc.. ment via the exhaust stack.

The release resulted because three separate machanisms failed to function as intended.

a. The vacuum was lost on the GEC0 primary confinement system because the vacuum isolation valve failed in a closed position as opposed to an open position.

b. The nitrogen purge line valves in the filter blowback system failed to completely s5ut off as intended causing special nuclear material to be discharged from primary confinement to the secondary confinement enclosure.

c. Ten of the 32 HEPA filters in the exhaust to the GECO secondary confinement system were improperly installed allowing special nuclear material to be discharged via the exhaust stack resulting in loss of special nuclear material to the atmosphere.

Region II was notified of the event by telephone on January 23, 1986, as a matter of courtesy rather than pursuant to regulations. The licensee provided Region II with a courtesy notification confirmation report on January 27, 1986. The NRC is currently reviewing the facts relating to the event to resolve if the loss of special nuclear material via the exhaust stack under these conditions is reportable pursuant to 10 CFR 70.52(a).

(86-03-01) 4 Event The inspector reviewed and discussed with licensee representatives the investigation findings and licensee corrective actions pertaining to the GECO conversion reactor event of January 22, 1986. The inspector informed licensee representatives that he had no comments regarding modifications and entrective actions and no objection to restart.

"An unresolved Item is a matter about which more information is required to determine whether it is acceptable or may involve a violation or deviation.

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a. Licensee Action Following the Event The licensee immediately initiated an investigation with a commitment not to operate the-GEC0 equipment until the Wilmington Safety Review Committee (WSRC) had reviewed the findings and the proposed corrective actions, and had approved restart of the GECO system. The licensee used consultants to review the details of the event and their proposed corrective actions.

The WSRC met on February 18, 1986, to review the licensee's investiga-tion findings and recommendations for corrective actions. The conaittee approved the restart of the GEC0 system pending implementation of the proposed modifications and corrective actions.

b. Results of Licensee's Investigation -

The licensee's investigation team concluded that as a result of a higher than normal pressure drop across the process filter, there was a decrease in the pressure drop across the conversion reactor. This decrease in pressure drop caused the reactor flame to go out. A restart of the reactor flame was automatically initiated. The licensee's investigation team concluded that the response time for the block valve to open for the disassociated ammonia (DA) feed was much less than the response tima for the block valve for the makeup air feed to open. Consequent y with the DA entering the system more quickly 1

than the makeup air, a flash-back was experienced causing a rubber hose feed line supplying tF.e DA to burn. This resulted in a small fire of short duration in the secondary enclosure surrounding the head end of the conversion reactor, ard the heat from the fire melted a heat sensing switch for shutting down the process (shuts of f UF6, air and DA feeds). The melting of the switch probably shut down the process.

Also, the melting provided a direct short of the power causing loss of power to the system including the control panel. The vacuum isolation valve closed causing loss of vacuum to the system. With loss of vacuum to the system and the nitrogen blow-back valves leaking nitrogen into the system, a positive pressure on the system was created with a nitrogen flow from the exit end of the conversion reactor vessel to the feed or head end. With the rubber DA feed line having burned, uranium oxide powder was discharged into the secondary enclosure from the open end of the feed hose. Also, some uranium oxide was expelled into the working atmosphere through a broken sight glass which had been repaired with tape. The uranium oxide in the secondary confinement was picked up by the normal exhaust system, and discharged through the fluoride scrubber, the HEPA filter bank, and the stack. Because ten of the 32 HEPA filters were not properly installed, approximately 800 grams of special nuclear material was discharged to the environment. Environmental and health physics significance of the incident are addressed in inspection report 70-1113/86-01.

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c. Licensee Initiated Corrective Action Corrective actions were to assure that the P& IDS were up-to-date and that equipment was installed as designed. The vacuum isolation valve was reinstalled to fail in an open position. A block valve was installed in the nitrogen supply line to fail in a closed position  !

and to be in a closed position during a shutdown mode. A flow meter was installed in the air supply line with sensors to indicate a ,

predetermined flow prior to opening of the DA supply block valve. The rubber feed line was replaced with a noncombustible feedline. The quality assurance program has been upgraded to assure that HEPA filters were installed properly and in accordance with written approved procedures. The broken sight glass was permanently secured rather than i taped. A pressure differential sensor was added across the conversion  !

reactor.

No violations or deviations were identified.

5. UF6 Cylinders and Cold Trapping (92706)

The inspector reviewed the licensee's procedures for weighing model 30A and -

30B UF6 cylinders and controls for assuring that any overfilled cylinders would be immediately identified, and management informed so that no further action would be taken until management approved the disposition of the cylinders.

T'he process engineer explained the recent changes and established controls in the cold trapping procedures to assure that the cold trap cylinder would not be overfilled. Safety margins and secondary checks were provided to assure that heating of overfilled cylinders was prevented. The inspector had no further questions or comments.

No violations or deviations were identified.

6. Nuclear Criticality Safety (88015, 88005)

a. Analyses The inspector reviewed several nuclear criticality safety analyses.

These rarged from minor procedural changes to major equipment installa-tions. The licensee categorizes nuclear safety requests according to the nature and the status of the request. Categories are:

• Returned to submitter Being analyzed

• Approved for installation

• Installation not acceptable

• Approved for operation Cancelled No analysis necessary

5 The inspector verified that approved methods were used for analyses, that reviews were made and were overchecked by authorized individuals, that preoperational audits were performed, that nuclear safety release / requirements were issued to operations / engineering, and that the nuclear safety review checklist was filled out and signed.

b. Audits A review of the reports of the second, third, and fourth quarterly audits performed by the nuclear safety engineers for 1985 were reviewed by the inspector. These reports reflect that many findings were identified and that nuclear safety management made an analysis to determine potential noncompliance with regulatory requirements. These items were highlighted to licensee management. The documentation reflected that corrective actions wcre taken for all findings and each was closed after review for adequacy. The inspector discussed with licensee management the importance of the licensee self-identification and correction of problems and the necessity of the licensee to mtat the five tests ider,tified in 10 CFR Part 2, Appendix C.

c. Alarm The inspector verified that the nuclear criticality safety evacur.tien alarm systcm was calibrated ard source checked in accordance the licensee's procedures.

d. Tours During tours of the plant, the inspector observed that unsafe geometry containers were not being used to store special nuclear material.

Approved shipping and operating containers were used to store and handle special nuclear material. Liquids containing special nuclear material were stored in safe geometry tanks. The licensee does not use raschig rings or similar poisons. The inspector discussed procedural requirements with several operating personnel and verified that operating procedures and documented nuclear criticality safety requirements were readily available to workers in the work areas.

No violations or deviations were identified.

7. Operations Review (88020)

During tours of the operating, storage and laboratory areas, the inspector verified that special nuclear material was stored and processed in accordance with licensee procedures and nuclear criticality release / require-ments. Discu:sfons with operators revealed that they had received nuclear

r-6 criticality safety and radiation protection training. They discussed the basic safety requirements of their work areas. Workers in the UPMP area gage a complete description of the operation of equipment in their area.

Housekeeping appeared acceptable in all areas. The inspector noted some unchained gas cylinders in one area. The cylinders were promptly secured.

No violations or deviations were identified.

8. Safety Committee (88005)

The inspector reviewed the minutes of several Wilmington Safety Review Committee (WSRC) meetings. The meetings and reports met the licensee's WSRC charter procedure, P/P 40-1, Rev. 7, WSRC. It was determined that activities of -he WSRC met the licensee requirements. Action items and assigned responsibilities for followup were identified and tracked.

No violations or deviations were identified.

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