ML19345D017
| ML19345D017 | |
| Person / Time | |
|---|---|
| Site: | 07001193 |
| Issue date: | 10/18/1980 |
| From: | Haughney C, Rouse L NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | |
| References | |
| NUDOCS 8012080790 | |
| Download: ML19345D017 (8) | |
Text
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o, UNITED STATES j
[' j NUCLEAR REGULATORY COMMISSION
.M ', f WASHING TON. D. C. 20555 3,
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%..'. '. '.' l QCT - 0 iS8q DOCKET N0.: 70-1193 LICENSE NO.: SNM-1174, AMENDMENT NO. 4 7
u APPLICANT:
Kerr-McGee Nuclear Corporation G
kJ FACILITY:
Pistonium Fuel Fabrication Plant, Cimmaron, Oklahoma
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SUBJECT:
SAFETY EVALUATION REPORT -- LICENSE AMENDMENT
.5 APPLICATION FOR DECONTAC NATION AND DISMANTLEMENT
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0F GLOVEBOXES AND PLANT EQUIPMENT BY THE A
O 24 KERR-MCGEE NUCLEAR CORPORATION CIMMARON, OKLAHOMA o
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d DOCKET NO. 70-1193, LICENSE NO. SUM-1174, AMENDMENT NO. 4 D_i scussipn, v er McGee Nuclear Corporation (KMNC) Plutonium Fuel Fabrication The e
Plant at Cimmaron, Oklahoma, is in a standby status.
Plutonium fuel fabrication operations are neither in progress nor planned. KMNC's general plans for decontaminating and decommissioning the Cimmaron plutonium plant are described in their letter dated November 8,1977. Parts I through III of the general plan have been authorized by the issuance of previous license amendments. Parts I and II, which involved dismantling of the low level 1qiuid waste floculator and the backfilling of retention ponds, have been completed. Part III, which involves dismantling of solvent extraction equipment used in liquid scrap ret.overy, is in progress.
Parts IV through VI, described in KMNC's letter of application dated January 8,1980, requests authorization to dismantle the remaining gloveboxes, process and laboratory equipment. The application also proposes that building internal surfaces and ventilation system be decontaminated for unrestricted release.
Tne equipment to be decontaminated and/or dismantled is described in KMNC's application dated January 8,1980 and consists primarily of:
(1) process ecuipment and gloveboxes in Rooms B-01, B-02,123,124,127,128; (2} 12: rat:ry and maintenance equipment in rooms 116 and 129 through 143; and (3) glovebox ventilation and intermediate filtration systems. The general steps necessary to dismantle a given glovebox require the disassembly and removal of internal equipment followed by disassembly and sectioning of the glovebox external structure. Disassembled internal equipment is sized such that it can be bagged-out of the glovetox then placed in a 55 gallon storage drum or specially sized storage container. The plutonium content on individual pieces is determined by Non-Destructive Assay (NDA) measurement prior to depositing the piece in a storage container.
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. Methods used Jto dismantle gloveboxes and their internal equipment have been previously described in detail in KMNC's amendment application dated November 29, 1978 for dismantling solvent extraction glovebozes 27A and B and in the NRC staff's safety evalution of the activity dated April 17,1979.
The present status of the process equipment is that it is shutdown, drained and no longer operational. Prior to its beinq placed in a shutdown status, this equipment and gloveboxes were decontaminated as part of the plant's cleanout campaign to remove recoverable quantities of plutonium. The amount of plutonium remaining throughout each glovebox, as determined by NDA measurement, is tabulated in Appendix X to KMNC's license renewal application for standby operations dated August 7, 1976.
II. Safety Considerations A.
Special Dismantlement Procedures Because of the unique nature of much of the equipment in the gloveboxes, several special dismantlement procedures are required.
These special procedures are described in detail in Section 1.3 of XMNC's application dated November 29, 1978 and in section III of KNMC's application dated January 8,1980. The first of these special procedures describes the glovebox bagout box that will be used to remove and package for shipment dismantled internal equipment. KMNC has used this bagout box during dismantling of the solvent extraction glovebox.
Another special procedure involves the use of a specially designed plasma arc torch. This special torch will be used to cut the 1cng pieces of thick piping and tanks. The special features of the plasma arc torch cutting system include a fine flame which reduces the total volume of weld splatter, a high cutting speed and a surrounding fire protection enclosure to contain the small amount of splatter that is created. The fire protection enclosure consists of a surrounding asbestos tent that is purged with nitrogen.
This special plasma arc torch cutting system has been constructed, mocked up and tested, using uncontaminated sections of schedule 80 piping, prior to its actual use on contaminated equipment.
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I Twenty wall storage tanks are installed in the common wall between Room B-01 and 127, and forty wall storage tanks are in the common wall between Rooms B-02 and 128. These stainless steel storage tanks have been placed into carbon steel sleeves imbedded in the walls. The walls teminate about three feet below the ceilings in Rooms 127 and 128. Tank dismantlement will require disconnection of connecting piping, raising the tanks up out of the sleeves and cutting short sections of each tank from the space between the top of the walls and the bottom of the ceiling. Difficulty in raising the tanks is anticipated because of close tolerances upon installation and the possibility of galvanic corrosion at the tank sleeve interfaces. As r
stated in their application dated January 8,1980, KMNC will provide for confinements and ventilation controls to prevent release of radioactive material to the building.
Underground liquid waste tanks outside the building have manways to allow personnel access. These tanks may remain in place if they can be deconta-minated. Otherwise, they will be evacuated and dismantled.
B.
L'uclear Criticality Safety The staff has established the nuclear criticality safety of the proposed operations with the inclusion of lice.1se conditions.
Ail ifquids will be packagec in containers whose diameters are no greater than 5.0 inches and whose volume is 4.0 liters. Although KMNC indicated the maximum quantity of plutonium per 208-liter shipping container (55 gallon drum) would be 5 g/ft3 (approximately 36 g/ drum), the plutonium content in the 4.0 liter containers, that are to be placed in the drums, is not
- r. assured when being loaded. They may not be measured (using NDA counting techniques) until after 10 containers have been accumulated.
Individual 4.0 liter containers with as much as 2.0 kg plutonium are less than 45 percent of critical, independent of the degree of water moderation and water reflection (" Nuclear Safety Guide TID-7016, Revision 2 NUREG/CR-0095" dated June 1978). Even if the results of the NDA measurements were low by a factor of two, the entire inventory of any given glovebox could not be made critical in a 4.0 liter or smaller container. The distribution of plutonium throughout the glovebox and the procedures for dismantling the equipment and gloveboxes preclude the addition of a large quantity of plutonium (certainly much less than 2.0 kg) in a single 4.0 liter container.
A license condition shall be added that authorizes the accumulation of a maximum of ~ ' kg plutonium in a single container whose capacity is
<4.0 liters, -
,stablish an upper limit to the authorized mass containe:.
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. The containers, awaiting NDA measurement, will be stored at a minimum edge-to-edge spacing of 60.96 cm (24 inches). The density analog method for array analysis was used by the staff to determine that an array of 10 containers with a maximum capacity of 4.0 liters / container
.is safe even if each one contained 2.0 kg plutonium. This is greater than the total plutonium content in the any given glovebox.
XM"C, in its planned procedures, did not consider methods for reducing the mass per container, if required (after NDA measurement), to the maximum requested for packaging in a drum. Therefore, a license condition shall be added that limits the number of containers (having a capacity of 4.0 liters) of plutonium to two at the station where the maximum plutonium content / container is to be reduced to 35 g.
The work station : hall be at least two feet from any other plutonium.
Each container, with no more than 35 g plutonium, is packaged in a 208-liter (55 gallon) drum or larger container.
Nuclear criticality scfety is assured in the storage and transportation of plutonium packaged in this manner in NRC approved shipping containers 10 CFR 71.9(e).
However, NRC (transportation) approval for the shipments is required pursuant to 10 CFR 71.42.
Equipment too large to be packaged in 208-liter drums will be NDA counted to determine its plutenium content and will be packaged and stored so that thg) package contains a maximum of 5 g plutonium 10 CFR 71 per/28 liters (5 g/ft the nuclear criticality safety of an array of these packages, independent of their number or spacing. The same 10 CFR Section may also be used as the basis -for the nuclear criticality safety of a mixed array of 208-11ter drums and larger containers packaged as described above.
A liquid level probe / alarm is activated should the liquid level in the bottom of a glovebox reach a depth of 2.5 cm (1.0 inches). A solution that contains 140 g plutenium/ liter would not be critical at twice this depth.
Although glovebox inventeries preclude a solution with this concentration on the floor of a glovebox, the alarm should be tested periodically to assure its operability as a precautionary measure. The liquid level probe / alarm is currently tested on a monthly basis (per telephone conversation with W. Norwood of KMNC on December 12, 1978).
However, no provision was made in the application for testing the alarm.
The present frequency for testing of the probe / alarm is adequate. Therefore, a license condition shall be added that specifies a minimum monthly frequency for testing th.a operability of the alann during the period in which the equipment and glovebox contain liquids.
, C.
Contamination Control A principal safety consideration during the dismantlement activities involves the monitoring and control of the potential spread of plutonium contamination.
Several factors included in KMNC's planned dismantlement activities combine to minimize, and otherwise mitigate, the potential for uncontrolled contamination spread. These factors are described below:
During dismantlement of the internal glovebox equipment, which is expected to contain much of the heavily contaminated material, the glovebox external structure will remain intact and a negative differential atmospheric pressure will be maintained from the outside to the inside of the glovebox.
In addition, the plutonium plant's building ventilation system will continue to function and operate as designed for normal plutonium fuel fabrication
- When dismantlement of glovebox external structures is in cperations.
progress, special greenhouse enclosures will be devised and special procedures will be used to prevent the spread of contamination. These special procedures and precautions are described in Sections III.2 and IV.2 of KMNC's application dated January 8,1980.
In addition, in each room which will oe involved in dismantlement activities, at least one constant air monitor with alam (CAM) will be operating. Also, as desc'ribed in Section IV.2 of the KMNC application dated January 8,1980, at least 50% of personnel working in respirators will be required to wear lapel air samplers.
Monitoring for surface contamination will be acccmplished in accordance with KMdC procedure KM-NP-10-66. Monitoring for nasal smears and bicassay sampling will be accomplished in accordance with KMNC procedure KM-NP-10-67.
Finally, glove and bag changing will be accomplished in accordance with KMNC procedure KM-NP-31-6.
These procedures incorporate requirements for activities when the plutonium fuel fabrication plant was in full opera tion. They are appropriate and satisfactory for the purposes of dismantlement activities authorized by this amendment.
D.
Control of Dismantlement Work The dismantlemant of gloveboxes and process equipment is a complex evolution that can be accomplished methodically and safely. At the KMNC Cimmaron plutonium plant, a small number of maintenance and health physics personnel remain. These personnel are experienced in plutonium plant maintenance and operational activities. The dismantlement activities will be conducted using this crew of experienced personnel and will normally be restricted to the day shift only. Cimmaron plant supervisory personnel will monitor the conduct of each day's activities to ensure that safe shutdown of dismantlement work is accomplished by the end of each shift.
If necessary, maintenance and health physics personnel can be retained on back shifts to complete necessary work. The activities planned by KMNC have been carefully planned, and their proposed undertaking can be accomplished in a safe fashion.
.. Individual dismantlement tasks associated with this amendment will be accomplished under the specific control of KMNC's Special Work Permit program. This program requires careful preplanning and delineation of specific safety requirements for individual activities prior to their initiation.
E.
Fire Protection Another important safety consideration involved in dismantlement activities is fire protection.
Details of the aspects of fire protection at the Cimarron plutonium plant are described in detail in Section 8 of the license application for standby cperations dated August 7,1976. The plant structure is constructed of fire-resistant concrete and steel. The building is canned twenty-four hcurs per day with operational and security personnel who can detect fires or hazardous conditions. Gloveboxes contain heat sensors and are connected
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to a fire d2tection alarm system. The plant telephone system can readily trigger the plant-wide public address system to announce the presence of a fire or other emergency.
When u' sing small portable torches for specific cutting operations that cannot be accomplished by other means, special precautions will be taken to ensure fire protection. These include preplanning and control using the Special Work Permit system described above. Secondly, portable fire extinguishers will be placed inside the tent or greenhouse enclosure for use by an operator. Because of potential problems that could arise with the use of a torch or open flame within the greenhouse enclosures, a license condition is included in this amendment requiring that special precautions be taken such that the flames or hot materials produced by cutting actions cannot ignite flammable materials in the greenhouse enclosure.
Gas lines and liquid lines will be evaluated as to their contents prior to sectioning.
Electrical cables and components will be deenergized prior to di sas sembly.
Picnt personnel are trained in the use of fire-fighting equipment and assigned to the fire brigade. Arrangements have been made with local fire departments to provide off-site assistance in the event of a serious fire.
Fire fighting and alarm eouipment is periodically inspected, and fire drills are held periodically. Preparations have been made to prevent, detect, control and extinguish plant fires.
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Ventilation Control Dismantlement activities authorized by this amendment have the potential to locally disperse plutonium contaminated material. Although this acterial is expected to be substantially in a dried solid form that is not readily dispersible, some of the cutting or other dismantling activities have the potential to cause local spreading of plutonium-bearing material. As a result, and as is normal practice during plutonium fuel fabrication operations, a key nethod of preventing the spread of contamination is the use of a properly designed and balanced ventilation system. This principle of prevention of contamination spreading through ventilation control also applies during the dismantlemant of gloveboxes and equipment.
Included in this method of ventilation control is the fact that the building's ventilation system and flows will be that designed for fuel fabrication operations. During the decorimissioning activities, two building supply and exhaust fans will be in operation. In addition, as described in Section IV.4 of the application, the exhaust stack air sampler and alarm system will be in constant use. During some dismantlemant activities the potential to alter building ventilation system ficas and differential pressures exists. As a result, a license condition is included with this amendment which requires the monitoring for ventilation flow and differential pressure imbalance and for corrective action to be taken promptly to restore proper ventilation flows and differential pressures.
III. Environmental Considerations The activities authorized by this amendment will take place in such a fashion that the overall status of the XMNC Cimmar'on plutonium fuel fabrication plant remains unchanged. The only plant liquid effluents are sanitary discharges. Dismantlement and packaging of the equipment and gloveboxes does not alter the confinement structures associated with the plutonium fuel fabrication plant building nor does it alter overall ventila-tien systems flows. As a result, any effect on the surrounding environment is insignificant. The issuance of this amendmant will not result in any changes in environmental impact and pursuant to 10 CFR Part 51.5(d)(4) an environmental impact statement or negative declaration and environmental impact appraisal need not be prepared in connection with issuance of this amendment.
I IV. Conclusions The dismantling, decontamination and removal of the equipment and glove boxes have been carefully planned by KMNC and based upon our review of the Termination Plan Parts IV, IV and VI as described in their application dated January 8,1980, the proposed controls, surveillance and audits are judged to be adequate for the safe and successful dismantling of this
., equipment. The nuclear criticality safety conditions associated with dismantling the equipment and its gloveboxes have been reviewed and are found to be satisfactory along with the incorporation of license conditions 3 through 7 included with this amendment. The radiation and contamination controls associated with this work will employ approved KMNC procedures.
The operational and adninistrative controls are judged to be within the experience capabilities of the personnel who will actually perform this work. NRC Office of Inspection and Enforcement, Region III personnel have been contacted and their suggestions and concents on the Termination Plan '.1 ave been incorporated into the overall review.
It is recomended that Amendment No. 4 to License No. SNM-1174 be approved.
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Charles J. Haughney Advanced Fuel and Spent Fuel Licensing Branch Division of Fuel Cycle and Material Safety
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Approved'N
.8rtv' I'~ C Rouse, CEief Advanced Fuel and Spent Fuel Licensing Branch
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