ML20236F085
| ML20236F085 | |
| Person / Time | |
|---|---|
| Site: | Paducah Gaseous Diffusion Plant |
| Issue date: | 06/23/1998 |
| From: | Toelle S UNITED STATES ENRICHMENT CORP. (USEC) |
| To: | Knapp M NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| References | |
| GDP-98-0119, GDP-98-119, TAC-L32067, NUDOCS 9807020016 | |
| Download: ML20236F085 (7) | |
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4 USEC A* Global Energy Company I
June 23,1998 GDP 98-0119 Dr. Malcolm R. Knapp Acting Director, Office of Nuclear Material Safety and Safeguards Attention: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Paducah Gaseous Diffusion Plant (PGDP)
Docket No. 70-7001 Criticality Accident Alarm System (CAAS) Monitoring Exclusion Request (TAC No. L32067)
Dear Dr. Knapp:
The purpose of this letter is to respond to the NRC's request (TAC No. L32067) for additional information on the Criticality Accident Alarm System (CAAS) Monitoring Exclusion Request for j
the C-710 Building. The request for additional information was provided to USEC in Reference I and identified additional information required by NRC to allow final action to be taken on the subject Certificate Amendment Request. The enclosure to this letter provides USEC's response to the request for additional information.
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This submittal completes USEC's response to the request for additional information (TAC No.
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L32067) provided in Reference 1. Should you have any further questions, please contact me at (301) 564-3309 or Marc Klasky at (301) 564-3408. There are no new commitments contained in this
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submittal.
Sincerely, g
g.A.
zo Steven A. Toelle Manager, Nuclear Regulatory Assurance and Policy
Enclosure:
As stated 9807o20016 980623 7 PDR ADOCK 07007001H C
PDR 2 cc: NRC Region 111 Office NRC Resident inspector-PGDP 6903 Rockledge Drive, Bethesda, MD 20817-1818 Telephone 301-564-3200 Fax 301-554-3201 http://www.usec.com l
Offices in Livermore, CA Paducah, KY Portsmouth, OH Washington, DC L
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Dr. Malcolm R. Knapp June 23,1998 GDP 98-0119, Page 2 l
REFERENCES L
1.
Letter from Robert C. Pierson (NRC) to Mr. James H. Miller (USEC), Criticality Accident
_I Alarm System Detection Monitoring Exclusion Request, Paducah Gaseous Diffusion Plant (TAC No. L32067), dated May 8,1998.
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Enclosure GDP 98-0119 Page1of5 Response to NRC Request for Additional Information (TAC No. L32067)
Paducah Gaseous Diffusion Plant Docket 70-7001 The Nuclear Criticality Safety Evaluation (NCSE) of the Building C-710 Drain System (NCSA Number 14923-25) Identifiesfour classes ofobjects which might be major sources ofinadvertent introduction ofuranium-bearing materialinto the drain system: cylinders, U-tubes, straight tubes, and coldtraps. Limits areplacedon the number ofthese which arepermittedto reprocessed. The limits are 120 cylinders / month, 250 U-tubes / week,16 straight tubes / week and30 cold traps / month.
These limits are required to be stated on appropriately locatedsigns. Concerning the operations im>olving these objectumd the associatedsafetypractices, thefollowing information is requested:
1.
Please identify the documents in which the administrative limits mentioned above are rejlected (NCSA/E, Procedure, etc.). Is a count kept ofhow many ofeach objects has beenprocessed each month?
NCSE 1493-25, NCSA 1493-25, and procedure CP4-TS-AS7002 identify the administrative limits of 120 cylinders / month,250 U-tubes / week and 16 straight tubes / week. A running count of these objects which have been processed for the time period required is maintained in logbooks.
None of the above documents contain the limit of 30 cold traps / month. There is a reference to a maximum of 30 samples a month (assumed to contain uranium equivalent to a metal cold
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trap) in NCSE 1493-25, Section 4.2.7, which addresses accidental disposal of a sample a day down the drain system. This quantity is used to establish the worse case boundary for samples
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and is not a limit on the use of cold traps.
2.
Where is this information kept? Is it available topersonnel mvolved inprocessing and cleaning these objects?
NCSAs, procedures, and logbooks pertinent to these laboratory operations are maintained in the laboratory area. These documents are available to personnel involved in processing and cleaning these containers.
3.
What is the normal monthly number ofeach ofthe abovefour classes ofobjects processed in Building C-710? What is the maximum historical number that has beenprocessed in a month?
a)
The normal monthly number of 2S cylinders is 20, with a maximum of 60 during May 1997.
b)
The normal monthly number of U tubes is 510, with a maximum of 908 during j
October 1996.
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d' Enclosure GDP 98-0119 Page 2 0f 5 c)
The normal monthly number of straight tubes is 10, with a maxi. mum of 40 during the month ofJanuary 1997.
d)
The normal monthly number and the maximum number ofcold traps processed in the C-710 building is not documented. An estimated total of 155 cold traps is processed j
in Building C-710 monthly. However, this number represents repeated use of a limited number of cold traps in use at a given time. There is no NCS requirement concerning the number of cold traps in use or processed.
2 4.
What happens ifl due to operations, the raumber ofobjects -to be processed exceeds the permitted monthly limit? Are the objects kept in Building C-710 awaitingprocessing?
If the number of objects requiring processing exceeds permitted weekly or monthly limits, the objects are stored in C-710 Room 21, under NCSA limits.
5.
What personnel are permitted to handle the above four classes of objects? Is there documentary evidence that thesepersonnel are trained, quahfied, andfully aware ofthe above safety limits and their sigmficance as a criticality safety concern?
Only personnel trained and qualified to work in the Sampling Laboratory of the Analytical Laboratory are permitted to perform cleaning operations involving the specified material containers. Training for these personnel that specifically addresses the criticality safety concernt includes the following (training documentation is on file):
1)
Training Module 401.09.04, " Handling of Uranium Cylinders in the Subsampling Laboratory" 2)
Training Module 401.89.15,"UF6 Sample Tube Cleaning" 3)
Training Module 401.89.20," Cleaning 2S Sample Containers" 6.
What abnormal events could occur that would cause the number ofuranium bearing objects being processed to increase? For example, would a cessation ofoperations cause a backlog
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that would have to be worked offat a near maximal rate? Are there operational situations in l
the cascade such that an abnormally large number of these sources would need to be l
processed? What is the maximum credible number of each of the four t.Spes of uranium-containing objects that might become available to processed in any one month?
1 Abnormal events that could cause an increase in the number of tubes requested to be processed include:
j 1)
Loss of field assay machines would increase the number of samples taken in U tubes.
2)
Increased sampling in C-360 would increase the number of samples taken in 2S l
cylinders.
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4 Enclosure GDP 98-0119 Page 3 of 5 3)
Halt in operation oflaboratory facilities could produce a backlog that would require processing at or near maximal. ate; however, no halt in cascade operation is credible that would increase sampling activities.
The maximum credible number of U tubes in use at any one time is estimated at 500 tubes which represents the approximate total number of U tubes available for use in the plant.
Under extreme conditions these could be cleaned and recycled within a two week period for a f
total maximum credible number of U tubes of 1000 per month. During the period October 2, I
1996, to May 11,1998, the laboratory processed an average of 118 U tubes per week with a maximum of 250 U tubes per week only being processed once.
The maximum number of 2S cylinders containing material that can be stored in the laboratory is 160. The maximum credible sampling capacity at the plant would be approximately 100 per l
month.
Straight tubes are only used for storage ofIsotopic standards. Cleaning of straight tubes is only required in the event of depletion of the standards. - There is no credible event which would
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cause excessive depletion ofisotopic standards. Over the past 18 months, the maximum number of straight tubes processed in one month was 40.
-7.
How are personnel designated to actuallyperform the monthly sampling of the C-712 acid neutralizationpit? Is it normally the sameperson each month? What are the qualifications of d
the personnel eligible to be assigned this task?
Personnel'are designated to perform the' sampling of the neutralization pit based on their sampling experience. Personnel designated to perform this sampling are initially trained by C-
.710 laboratory personnel who are knowledgeable in a wide variety of sampling processes.
Personnel are provided On-the-Job Training (OJT) on the principles and practices necessary
- to perform the sampling as required by the requestor. Once OJT on CP4-EW-EV2303,
'" Sampling of Containerized Wastes" has been completed, the personnel may perform the
- sampling unsupervised. CP4-EW-EV2303, applies to sampling of tanks, pits, and other i
containers.
The sampling of the C-712 acid neutralization pit is coordinated by an Environmental Monitoring supervisor or designee. The Environmental Monitoring supervisor.
or designee and the Environmental Monitoring technicians are required by CP4-EW-EM1103,
" Training Guidelines for Environmental Monitoring Departmental Personnel" to be properly trained prior to performing sampling tasks. A list of the OJT approved personnel can be accessed on the ES&H Training Data Base, j
Several people are qualified to perform the sampling process. People are chosen each month based on the workload of that individual.
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c, Enclosure GDP 98-0119 Page 4 of 5 Minimum requirements of the personnel eligible for the task include Radiological Worker II training, Confined Space Training,40 Hour HAZWOPER training, and completion of OJT for sampling of containerized waste.
8.
What is thefunctional title ofthe supervisor responsiblefor assuring that the monthly sampling and measurement ofC-712 isperformed and that results are within limits and normal? What means are used by this supervisor to assure that he/she would be aware ifthe sampling and measurement were not done? What would assure that this oversight function would be performed even ifthe usual supervisor were on extended vacation?
The supervisor for the Radiochemistry Laboratory or his designee is responsible for assuring that the monthly sampling and measurement of C-712 is performed and the results are within limits. The sampling event has been entered in the Instrument Calibration and Maintenance System (ICMS) to prompt the initiation of the request for sampling. The s'ampling events are initiated by the Environmental Compliance organization through this request. Environmental Sup; art sampling crews perform the sampling function. The oversight function is dually assigned with the lead responsibility assigned to the supervisor of the Radiochemistry Laboratory and the alternate person being the supervisor for the Organic and Process Analysis Laboratory who is also the facility owner for the C-712 pit.
9.
Are the results of the monthly sampling of C-712 documented and retained? Are these documented results verified by the QA fumet lon, the NCSfunction, or some otherfunction independent ofthe organization responsiblefor Building C-710 and C-712 operations?
Results are documented through the Laboratory Information Management System (LIMS).
Results are entered into the LIMS system upon completion. No personnel outside the Laboratory organization verify the C-712 pit analyses.
- 10. It is stated that two methods are used to measure the uranium content ofcertain samplesfrom C-712, gamma spectroscopy and " analysis. " Does the latter refer to wet analytical chemistry?
Are these two measurements made by two different persons and in an independent manner.1 1s this a written NCS requirement? How can compliance with this be verified?
Gamma Spectroscopy is the method of analysis required for all the C-712 pit samples by NCSE 1493-25. The difTerence in the analysis of samples is that samples from the bottom sludge layer are allowed to settle prior to analysis. Independent analysis methods and personnel are not required by NCSA 1493-25.
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Enclosure GDP 98-0119 Page 5 of 5
- 11. Is Building C-710 and the area immediately adjacent to it above ground covered by a Criticality Accident Alarm System (CAAS)?
Areas containing fissile material operations in C-710 have been demonstrated to have CAAS detection coverage. In addition, the CAAS is audible immediately outside the C-710 Building.
For all areas that have CAAS detection coverage, audibility is provided for the entire building (inside) plus a 12 Rad evacuation zone surrounding the perimeter of the building.
- 12. How many coldtraps are typicallyprocessedin Building C-710per month? Is there a criticality safety requirement (in NCSE 1493-02?) limiting the number ofcold trapsprocessed in C-710 per month? Section 4.2. 7 ofthe NCSE ofNCSA number 1493-25 Rev. 2 considers a scenario where the contents of30 cold traps per month at 3.81 kg U are erroneously disposed ofdown the drains, but this value of30 is not stated to be an NCS administrative control.
An estimated total of 155 cold traps are processed in Building C-710 monthly. However, this number represents repeated use of a limited number of cold traps in use at a given time.
Typically, no more than 16 cold traps are in use at a given time.
The number of cold traps processed in C-710 per month is not administratively controlled by an NCSA. NCSE 1493-25 relies on the control that rinse solution from any equipment having visible contamination be collected and disposed in the liquid uranium salvage. The value of 30 samples (assumed to contain uranium equivalent to a metal cold trap) emptied into the drain system per month was presented in NCSE 1493-25 as a " worst case" scenario (i.e., pouring the entire contents of an item with the greatest uranium mass each day into the drain). NCSE 1493-25 further argues that since this bounding case is suberitical, sampling the pit on a monthly schedule to ensure that large quantities of uranium are not introduced into the pit maintains double contingency.