ML20028A722
| ML20028A722 | |
| Person / Time | |
|---|---|
| Site: | 07002964, 07002965 |
| Issue date: | 10/28/1982 |
| From: | Jackie Cook CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | Jennifer Davis NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| References | |
| 19381, 21555, NUDOCS 8211240312 | |
| Download: ML20028A722 (12) | |
Text
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Jernee w cook T W /7 Vice President - Projects, Engineering and Construction 396ss General offices: 1945 West Parnail Road, Jackson, MI 49201 e (517) 78&O453 October 28, 1982 q) e RECBVED b
NOV 81993 y f;t John G Davis, Director N,@g
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Office of Nuclear Material Safety and Safeguards NME US Nuclear Regulatory Commission Mail sectma g
Washington, DC 20555 CV
'u DOCKU G HOVi 51982 MIDLAND NUCLEAR C0 GENERATION PLANT p.,
MIDLAND DOCKET NOS 50-329, 50-330 C
cj SPECIAL NUCLEAR MATERIAL LICENSES
-c SECURITY PROVISIONS FOR FISSION CHAMBER ASSEMBLIES 7.
sgnon FILE: B13.6 SERIAL:
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REFERENCES (1) J W COOK LETTER TO J G DAVIS (NRC), SERIAL 17297 g
DATED JUNE 22, 1982 (2) J W COOK LETTER TO J G DAVIS (NRC), SERIAL 18435 DATED AUGUST 12, 1982 ENCLOSURES (1) SECURITY MEASURES FOR FISSION CHAMBER STORAGE (2) FISSION CHAMBERS AND THEIR PERMANENTLY INSTALLED LOCATION On June 22, 1982, pursuant to 10 CFR Part 70, Section 70.3, Consumers Power Company submitted an application (Reference 1) requesting the NRC issue Special Nuclear Material Licenses to receive, inspect, possess, store, use and transfer fission chamber assemblies for and at the Midland Plant Unit 1 and Unit 2, Midland, Michigan.
In our correspondence of August 12, 1982 (Reference 2), we advised that we would receive, store, inspect and transfer the fission chamber assemblies in the same manner as material which is presently handled and stored under the Plant's NRC approved Materials License No 21-08606-09, Amendment No 4 as issued on May 28, 1982. This method of handling and storing radioactive material, as well as a description of the controlled access areas and mat-rial accountability procedures, is described in Appendix D, Exhibit D-III c Reference 1.
As requested by the Staff, we are providing supplemental information to further detail the security measures which will be implemented for the storage of the fission chamber assemblies in their temporary storage location prior to their installation for operation. These security measures for the temporary on-site storage of fission chamber assemblies are described in Enclosure 1 Based on discussions with the Staff at the site meeting held;on Septendte Amii oc1082-0256a100 MN 8211240312 021028 f/
PDR ADOCK 07002964 C
2 1982, it is our understanding that the precaations detailed in Enclosure 1 meet the Staff's guidelines for the quantity of fissile material present. describes the fission chamber assemblies in their installed
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operating location adjacent to the reactor vessels.
Based on the description contained in Enclosure 2, we believe that the ex-core neutron-flux detectors are highly inaccessible, requiring the use of a crane, several large tools which c3nnot be easily concealed and a considerable amount of time, ie, hours, to effectively remove them. Furthermore, the location in which the detectors will be installed will be within an area to which access will be administratively controlled. For these reasons and due to the small quantity of U-235 isotope involved, ie, less than 15.0 grams per reactor unit, sufficient protection will exist for the installed neutron detectors with no need for additional security measures.
JWC/RLT/bjb CC RJCook, Midland Resident Inspector, w/o RWHernan, NRC, w/a (2) oc1082-0256a100
' ENCLOSURE I SECURITY MEASURES FOR FISSION CHAMBER STORAGE The following is a description of security measures which shall be put -into effect upon delivery of the fission chambers :to the Midland Plant site.
1.1 STORAGE AREA 1.1.1 Upon delivery, the fission chamber assemblies (as described in
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-Enclosure II) shall be placed in a locked trailer within a locked enclosure constructed of ' chain link fence approximately 7 feet in height.
1.2.1 Lock and key control procedures shall be developed to assure that only authorized personnel have access to trailer keys.
Personnel authorized access to these-trailer keys are the Plant Health Physicist, Senior Health Phycicist, Chemistry / Health Physics Superintendent, Radioactive Material Control Supervisor, Reactor Engineer, Administrative Superintendent, Property Protection Supervisor, or their designates.
1.3.1 Patrols shall be made of this area at least twice per 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> shift to.
detect unauthorized activities.
Security officers conducting these patrols shall be equipped with radios capable of communicating with a continuously manned security post and other officers on duty. The security post has the ca; ability of contacting local law enforcement agencies to respond to intrusions of this storage area. The primary LLEA contact for the Midland Plant is the Midland City Police Department.
2 2.1 AREAS OF USE The use areas for the fission chamber assemblies are described in Enclosure II.
Due to the difficulty in obtaining access to the assemblies and the small amount of material in place per unit, there vill be no special security measures required.
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ENCLOSUKE II a
l FISSION CHAMBERS AND THEIR INSTALLED OPERATING LOCATION i
1.0 General Information 4
i The Midland Nuclear Cogeneration Plant application for Special Nuclear Material Licenses was submitted by Consumers Power Company to the NRC on June 22, 1982. An integral part of this application was the request for I
the issuance of Special Nuclear Materials Licenses for ten (10) fission chambers. These ex-core fission chambers will be used in a neutron flux l
monitoring instrumentation system to satisfy the intent of Regulatory Guide 1.97 (Revision 2, December 1980).
2.0 Fission Chamber Description Two neutron-flux detector assemblies per reactor unit will be installed
'in each of the Midland Units 1 and 2.
A fifth detector assembly, a c
i spare, will be stored on site. The functioning length of the detector assembly is 59.2 inches long, and this portion of the detector has an j
0.D. of 5.25 inches. Attached to the cable end of the functional portion of the detector assembly is a smaller diameter 35.3 inch long aluminum tube through which the composite detector cable passes,and which supports 4
the functional portion of the detector. The total length of the neutron l
detector assembly, excluding the integral cable, is 94.5 inches.
Its I
weight without the integral section of cable is approximately 50 pounds.
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It is constructed from a commercial grade aluminum alloy tube which-is sealed at both ends.
Each detector assembly contains two 48-inch.long, 2-inch diameter aluminum fission chambers.
Each fission chamber contains uranium isotopes enriched in the U-235 isotope to approximately 93.13%, and each has an as-manufactured tntal quantity of uranium, representing several isotopes, which ranges from a minimum of 3.817 grams to a maximum of 3.917 grams, depending on the individual fission chambers used in the i
detectors manufactured for the Midland Plant. With an enrichment of I
j 93.13 weight percent, the maximum resulting quantity of U-235 isotope l
present in any one fission chamber is, therefore, less than or equal to 3.648 grams. And the total quantity of U-235 isotope present in any two i
i neutron detector assemblies combined, representing' the number of f
detectors installed per reactor unit, is less than 14.59 grams. The uranium material is contained within the sealed fission chambers in the-i form of a coating which cannot be easily separated from the fission i
chamber.
Heavy construction coaxial cables from the two fission chambers in each neutron detector are bundled together and exit the top end of the neutron detector assembly through a sealed, one inch (1") I.D. flexible stainless i
steel hose. This metal hose is jacketed with a stainless steel braid.
The integral composite cable for each detector is approximately 46 to 69
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feet long, depending upon the detector, and this cable is terminated at f
the first junction box exterior to the concrete primary shield.
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3 3.0 Description of Installed Detector Location This description applies to both the Midland Unit 1 and Unit 2 reactor buildings which will be the installed operating locations for the ex-core neutron detector assemblies. The following information describes the detector locations as illustrated on the attached Sketches NDL-1 and NDL-2.
1 Two neutron detector assemblies are installed symmetrically on opposite sides of the reactor vessel in 6 inch diameter, schedule 40, thimble wells. These thimble wells, as shown on Sketch NDL-1, are permanently anchored to the primary shield walls just below the level of the refueling canal floor at elevation 634'-0" and extend downward between the reactor vessel insulation and the concrete primary shield. As shown on Sketch NDL-2, each neutron detector assembly, containing two fission chambers, is suspended 17'-6" below the refueling canal floor within the thimble wells. Each detector is suspended by-1/4 inch diameter stainless steel links attached to a 5 inch diameter, 28 inch long concrete-filled shield plug, through which the single composite neutron detector assembly cable passes. The combined weight of both the shield plug and suspended detector assembly is estimated at 100 pounds. Above the shield plug is a heavy steel pull box, through which the composite detector cable passes and which is packed with borated silicon resin beads for shielding. The 1/4 inch thick watertight service plate covering this pull box is secured along its perimeter with approximately twenty-five 1/4 inch flat head countersunk bolts.
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.The neutron detectors will be installed in the thimble wells, with access to the area of the refueling canal limited by administrative controls, after tb-plant has completed the hot function testing program and prior to fuel load. After installation and electrical checkout of the detectors, the refueling pool to reactor vessel seal plate will be lifted by the reactor building overhead polar crane and placed in either its storage location or in its functional location on the refueling pool floor at approximate elevation 634'.
The seal plate is a 1-1/4 inch thick steel plate annulus with an outside diameter of approximately 23 feet 5 inches. This seal plate weighs approximately 11,900 pounds and would require the use of either the I
reactor vessel head-mounted monorail or the reactor building polar crane to lift it.
In its functional position indicated on Sketch NDL-1, the Fdal plate is secured over the top of the detector pull boxes with approximately thirty (30) lever-type clamps. The seal plate's storage location is directly over its functional location and rests on folding l
storage arms which are attached to the walls of the refueling canal.
In 1
its storage position directly over the d:tector pull boxes, the bottom surface of the seal plate rests at elevation 639'-61/8"-
Due to the long length of the detector assemblies, the refueling seal plate, whether in its functional or storage position, must be lif ted by j
either the reactor head-mounted monorail or the reactor building polar crane for the neutron detector assemblies to be completely removed from l
the thimble wells.
mi1082-2923a100
4.0 Conclusions The preceding description of the installed neutron detectors demonstrates the high level of inaccessibility afforded these detectors as installed-in their operating locations. Further security measures would not contribute'significantly to the type of " location" protection already provided. Accordingly, it is our conclusion that no additional security measures are warranted for the detectors in their installed operating locations.
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DOCKET NO. 50-329 and 50-330 I
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r CONSUMERS POWER COMPANY Midland Units I and 2 Docket No 50-329, 50-330 Letter Serial 19381 Dated October 28. 1982 At the request of the Commission and pursuant to the Atomic Energy Act of 1954, and the Energy Reorganization Act of 1974, as amended and the Commission's Rules and Re;ulations thereunder, Consumers Power Company submits a discussion of the security measures which vill be implemented during the temporary storage of the neutron-flux detector assemblies onsite along with a i
description of the detector assemblies installed in their operating locations.
CONSUMERS POWER COMPANY By JW 'ook,'Vice President Projec
, Engineering and Construction Sworn and subscribed before me this _j__ day of November. 1982 Notary Public
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Jackson County, Michigan My Commission Expires September 8, 1984 l
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