ML20028A026
| ML20028A026 | |
| Person / Time | |
|---|---|
| Site: | 07001113 |
| Issue date: | 11/05/1982 |
| From: | Bidinger G NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | |
| Shared Package | |
| ML20028A019 | List: |
| References | |
| NUDOCS 8211160282 | |
| Download: ML20028A026 (3) | |
Text
DISTRIBUTION:
Docket File 70-1113 PDR NMSS rf NOV 5 1982 FCUP rf GHBidinger (2)
LTyson WTCrow JBlaylock LJEvans JRobertson DOCKET NO: 70-1113 Region II LICENSEE:
General Electric Company (GE) l Wilmington Manufacturing Department (WMD)
SUBJECT:
SAFETY EVALUATION REPORT RE USE OF NEUTRON ABSOR8ERS FOR NUCLEAR CRITICALITY CONTROL, AMENDMENT APPLICATION DATED SEPTEMBER 8,1981, AND SUPPLEMENT DATED AUGUST 13, 1982, 70-1113040S I.
Background
In the subject application, GE requested authorization to use fixed neutron absorbers in the WMD facility and proposed a specific use of cadnium panels with existing slab tanks. In a November 30, 1981 letier to GE, additional information on use of the cadmium systems was rqquested, and it was suggested l
that the application be limited to the cadmium systems. On August 13, 1982, l
GE provided supplemental information on use of the cadnium systems and limited the amendment application to cadmium and boron.
II. Discussion A.
License Amendment for Ffwed Neutron Absorbers l
i In the November 30, 1981 request for additional information, the NRC l
reviewer suggested that the request for use of fixed neutron absorbers be limited to cadmium in stainless steel sheaths. In the August 13, 1982 l
supplement (Attachment 3), GE limited the proposed use of sfixed neutron absorbers to cadmium and boron. The staff finds the proposed use of cadutum and boron to be acceptable bec:use there is sufficient critical mass data available for salidation of reactivity calculations using boron or cadstum as fir.ed neutron absorbers.
In Attachment 3. GE has also cvnsuitted to (a) having fixed neutron absorbers sealed in stainless steel or other suttable containers, (b) having the fixed I
absorber system installed as a permanent part of the process equipment. (c)
L demonstrating the effectiveness of the fixed neutren absorber system by validated reactivity calculations, and (d) having contml systems to verify I
the presence of the absorbers.
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NOV 5 B82 The staff finds that GE's proposed license amenhent for general use of fixed neutron absorbers is acceptable in all aspects except that GE does not require that the presence of the neutron absorber and proper installa-tion of the neutron absorber system be; verified prior to first use. Accord-ingly, the staff recommends the following license condition:
i The use of neutron absorbers for criticality control as described in Attachment 3 of the August 13, 1982 letter, 1s authorized provided that the licensee, using written procedures developed and approved in a manner established by licensee management, shall inspect the fixed neutron absorber system to verify the presence of the neutron absorbers and shall verify that the system installation is in accordance with design and nuclear criticality safety requirements. Such inspections shall be conducted prior to using the systens neutron absorber for ncclear criticality control. Records of such inspections shall be documented and maintained fbr the life of the system.
A.
Stainless Steel-Cahtum-Polyethylene-Stainless Steel Panels In the amenhent application, GE proposed to use SS-Cd-Polyethylene-SS panels on both sides of existing large slab tanks in the radwaste area.
GE attributed the need to:
(a) bulging of the slab tanks and (b) use of the GECO process for production of U02 powder. GEC0 powder may have a higher bulk density than ADU-produced powder.
Each pair:af cadmium and polyethylene sheets is sheathed in 65 mills of stainless steel to fem panels which are 94 inches x 40 inches x 1.2 inches.
Each panel contains a 1/4-inch tube fitting to pemit pressure testing after fabrication and after installation. Such tests provide assurance of continued sheathing of the cadmium from the chemical environment of the WMD facility.
Twelve panels (six on each side) are used to poison the slab tanks which are 8 feet high by 20 feet long. Eat'i panel, with the cahtum sheet toward the slab tank, is wedged against tt. slab tank frenework.
4 In response to staff questions on the use of the cd-polyethylene panels, GE provided additional design and test procedures to ensure that cahtum was actually placed insin the SS sheath, that the Cd sheet will remain in place, inside the sheath, and that the cd-polyethylene orientation inside the sNath is known.
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NOV 5 1982 GE performed neutron scanning measurements which confirmed the presence of cadmium and established orientation of the cd-polyethylene sheets in the sheath. Positive marks were placed on the top of each panel indicating that the cadmium side wastto be located against the face of the slab tank.
i Staff calculations of tank reactivity indicated that revec2ing the panels, 1.e., polyethylens against the tanks, would cause criticality ur. der the r
conditions of optimum moderation of UO2 powder in the tanks. GE did not j
provide information which assures that the panels were actually installed with the cadmium side of the panel oriented toward the face of the slab tanks. Accordingly, inspection of the inctalled panels prior to initial use, as required by the above license candition, issvery important.
In the September 8,1981 application, GE reported a WMD safety limit (Reff) of 0.97.
It shouYd be noted that the reactivity limit in the license is 0.90 and is applicable to all uses of neutron absorbers approved by GE under the " broad license." The proposed license amendment for the general use of fixed neutron absorbers does not request a change in the reactivity limit in the license.
The September 9,1981 application Attachment 1 and Attacionent 2. describee the tanks as being 10 feat high. The criticality analysis, Appendix B of, and the independent KRC staff ar.alysis, correctly use 8 feet i
as the tank height.
III. Conclusion and Reconsnendation The proposed use of fixed neutron absorber systems on process equipment, including the radwaste/ quarantine slab tanks, can be used to safely azure nuclear criti-cality safety. Because 'here is no increase in risk of nuclear criticality safety, j there should be no increase to public health and safety or to the protection of the environment.
Approval of the application is recomunended.
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George H. 81dinger Uranium Process Licensin.g Section Uranium Fuel Licensing branch Division of Fuel Cycle and Material Safety, NMSS Original Signed By:
Approved by:
W. T. Crow, Section Leader i
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