IR 05000057/1990004
| ML20028H673 | |
| Person / Time | |
|---|---|
| Site: | University of Buffalo |
| Issue date: | 01/14/1991 |
| From: | Austin M, Bores R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML20028H671 | List: |
| References | |
| 50-057-90-04, 50-57-90-4, NUDOCS 9101250067 | |
| Download: ML20028H673 (4) | |
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i U. S. NUCLEAR REGULATORY COMMISSION
REGION I
Report No.
50-57/90-04 Docket No.
50-57 License No.
R-77 Category 1 Licensee:
State University of New York tt Buffalo Rotary Road, South Campus Buffalo, New York 14260 Facility Name:
Buffalo Materia _1_s Research Center Inspection At:
Buffalo, New York
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Inspection Conducted:
December 18, 1990 Inspector:
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M. A. Kustin, Radiation Specialist-
/ dajk Effluents Radiation Orotection Sectie,,
Facilities Radiological Safety and Safeguards Branch, Division of Radiation Safety and Safeguards
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h. Bortd, Chief,h SF
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Approved by:
R. J date Effluents Radiation Protection Section, Facilities Radiological Safety and Safeguards Branch, Division of Radiation Safety and Safeguards inspection Summary:
Inspection Conducted on December 18, 1990 A m s Inspected:
Special inspection by one region-based inspector to review t h-tatus of the licensee's plans and activities pertaining to the repair and w :lication of the reactor tank.
Results: No violations were identified. The licensee had removed most of the reactor-related equipment from the tank, except for the plenum and some remaining beam tube stubs. The cutting of the core outlet pipe in preparation for plenum removal was observed. Data recorded in the licensee's documenta-tion system for monitoring worker radiation exposures were examined.
The inspector determined that the license was implementing good contamination control and exposure centrol practices.
v101250067 910117 PDR ADOCK 05000057 g
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DETAIL _S 1.0 Individuals Contacted
- L. Henry, General Manager, Buf falo Material Research Center (BMRC)
M. Adams, Acting Operations Manager, BMRC
- D. Dooley, Consultant
- Denotes those present at the December IB,1990 exit interview.
2.0 Operations At the time.of the current inspection, the water remaining in the reactor tank was approximately ankle-deep, and the plenum was in the process of being cut free for removal.
The plenum support legs had been cut and removed, and the plenum was held in place by overhead crane rigging and was attached to the tank wall by the core outlet pipe.
The core outlet pipe had to be cut to allow the plenum to be removed from the reactor tank, After.the plenum was removed, the licensee planned to remove the remain-ing beam tube ~ stubs and emove any residue from the reactor tank bottom.
Follosing this, the licensee planned to perform an external radiation survey to determine where temporary shielding may be needed to protect personnel within the tank.
One such area already identif'ed was along the tank wall that had held the previous thermal column.
Prior'to' removal of the plenum, an outside contractor had made measure-ments of.the vertical distance between the control bridge and the top of the plenum, and of the horizontal distances between the sides'of the plenum and the tank walls.
To minimize personnel radiation exposure, these measurements were made by individuals standing on the Control Deck
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level, using plumb bobs lowered into the reactor tank by strings.
The outside contractor will repair the existing liner, and fabricate and install a new liner.
A hydrostatic test of the existing liner will be done af ter it is repaired, and of the new liner af ter it is installed.
- The licensee plans to install leak detection capability to identify any leakage between the two liners.
The licensee projected that the work to be
'done by the outside contractor would be-started in late December, 1990 and completed in June, 1991.
3.0 Facility four The inspector observed most of the licensee's activities involved in cutting the core outlet pipe. One worker was at the tank bottom, using a reciprocating saw to cut the pipe, while a second worker was at the shelf level to assist.
A health physics (HP) technician was constantly present at the control l
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deck level to directly observe the workers' activities. Both workers in the tank wore Powered Air Purifying Respirators (PAPRs) with hoods, which provided each of them with a Protection Factor (PF) of 1000 for respiratory protection, i
l The inspector observed that a low-volume air sampler (with an approximate flow rate of 20 liters per minute) was continuously sampling for possible
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airborne radioactivity within the reactor tank during worker activities.
The inspector also observed that a continuous air monitor (CAM) with an audible alarm was operated at the control deck level to promptly identify any unexpected airborne radioactivity outside of the reactor tank.
The inspector observed that the licensee was implementing good contamina-tion control measures during the removal of components from the reactor tank. Access to inside the tank from the control deck was restricted to a single entry point within a roped-of f area.
The floor within the roped-off area was covered to minimize facility surface contamination.
Personnel access to the roped-off area was limited to only those with a specific task to perform, and all Aersonnel in this area were required to wear protective clothing, including shoecovers.
The inspector observed that proper frisking for personal centamination was being performed on individuals exiting the roped-off area.
No violations or deficiencies-were identified.
4.0 Records Review The inspector reviewed various licensee records and documents associated with the ongoing-reactor tank repair activities.
4.1 Bioassay Records The inspector reviewed records of in-vivo body _ counts of outside contractor personnel performed by a vendor's mobile counter on
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November 15, 1990. The in-vivo count data were analyzed for a broad mixed-fission product " library" of radioisotopes. Of the sixteen individuals counted, none exhibited detectable internal depositions for the isotopes being analyzed.
4.2 Internal Exposure Control The inspector examined the " Personnel-MPC-HR Tracking Log" maintained
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by the licensee for each individual _ working on the reactor tank repairs, Typical airborne radioactivity concentrations observed during the repair work done to date were approximately 0.5% of the maximum permissible concentration (MPC) averaged over the_ time required to perform a task during the work day.
Actual worker exposures observed to date-were typically negligible (i.e., less than IE-6 MPC-HR),
based upon air sarpling results and taking into account a PF of 1000 for respiratory protection when a-PAPR was used.
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4.3 External Exposure Control Based on inspector observations and discussions with the licensee,
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each worker involved with the reactor tank repairs wears two Indirect Reading Dosimeter (IRD) pocket chambers and a film badge. The IRD pocket chambers are read out daily.
The IRD results are used to promptly monitor and help maintain individual worker exposures below 100 millirem per week, which the licensee has established as an administrative control limit during the current tank repair project.
The film badge dosimeter is reaa out every two weeks for determination of the final " exposure of record".
The IRD and film badge data are graphed for each worker performing repair activities in the reactor tank.
The inspector observed that almost all worker exposures were
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below the licensee's weekly control limit, with the exception of one individual who had received an apparent exposure of 130 millirem in one week when-he had been the operator-of the reciprocating saw at the tank bottom during an unexpectedly long cutting operation.
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- No violations or deficiencies were identified.
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5.0 Exit Interview-The inspector met with the licensee personnel denoted in Section 1.0 on December 18, 1990. The scope and findings of the irsnection were discussed at that time.
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