ML20056B367
| ML20056B367 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 08/09/1990 |
| From: | Larkins J Office of Nuclear Reactor Regulation |
| To: | SOUTHERN CALIFORNIA EDISON CO. |
| Shared Package | |
| ML20056B368 | List: |
| References | |
| NUDOCS 9008280185 | |
| Download: ML20056B367 (5) | |
Text
,
4;
.a
- (.
X UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION In the Matter of SOUTHERN CALIFORNIA EDISON COMPANY.
SAN DIEGO GAS 8 ELECTRIC COMPANY, Docket Nos. 50-361 THE CITY OF ANAHEIM, CALIFORNIA, AND and 50-362 THE CITY 0F RIVERSIDE, CALIFORNIA (San Onofre Nuclear Generating i
Station, Unit Nos. 2 and 3)
EXEMPTION I.
The Southern California Edison Company, San Diego Gas & Electric Company, The City of Anaheim, California, and The City of Riverside, California (the licensee) hold Facility Operating License Nos. NPF-10 and NPF-15, which authorize operation of the San Onofre Nuclear Generating Station, Unit Nos. 2 and3(thefacilities). The licenses provide, among other things, that,the h
facilities are subject to all rules, regulat'ons and orders of the Nuclear l
Regulatory Commission (the Commission) now'or hereafter in effect. These 1
facilities are pressurized water reactor', located in San Diego County, California.
II.
Section (a) of 10 CFR 70.24, " Criticality Accident Requirements" requires that each licensee authorized to possess special nuclear material shall main-tain'in each area where such material is handled, used, or stored, an ap-propriated criticality monitoring system.
In accoroance with Section (a)(1) of i.
l.
10 CFR 70.24, coverage of all such areas at San Onofre Nuclear Generating Station, Unit Nos. 2 and 3, shall be provided by two criticality detectors.
i However, exemptions may be authorized pursuant to 10 CFR 70.14, provided that o
9008280185 900020 PDR ADOCK 05000361i.
1 l
P_
PNU
. =.,
2 the licensee has shown that good cause exists for the exemption, as allowed by 10 CFR 70.24(d).
In pa-ticular, Regulatory Guide 8.12, revision 2. "Criti-cality Accident Alarm System," states that it is appropriate to request an exemption 10 CFR 70.24 if an evaluation determines that a potential for criticality does not exist, as for example where geometric spacing is used to-a prelude criticality.
By letter dated March 27, 1984, the licensee requested an exemption to the requirements of 10 CFR 70.24. This exemption was granted by the Commission by letter dated September 28, 1984. However, since the granting of the exemption in 1984, the San Onofre Unit 2 and 3 have been granted amendments (Unit 2 Amendment 87 and Unit 3 Amendment 77) to their Technical Specifications which allow an increase in the storage capacity of their spent fuel pools. As a result, the bases for the original exemption was c. hanged by use of new high density storage racks in the spent fuel pool.
(The bases for the September 28, 1984 exemption for the existing new fuel storage racks did not change.) As a result, by letter dated July 5,1990, the licensee for the San Onofre Units 2 and 3 requested to revise the bases of the exemption for the San Onofre 2 and 3 spent fuel storage areas of the fuel handling building.
specifically,.the licensees proposes to continue to handle and store both irradiated and unirradiated fuel in the fuel handling building without having the two criticality monitoring systems required by 10 CFR 70.24.-
The bases for the current exemption is the potential for accidental criticality is precluded due to geometric spacing. The rationale for the requested exemption is the high density spent fuel storage racks. Under the amendments which granted an increase in the capacity of the spent fuel pools, it was recognized that criticality was precluded by the following:
(1)geo-
metricspacing;(2)Boraflexpanelsinsertedintheracks;(3)minimumboron concentration in the spent fuel pool of 1850 ppm per Technical Specification 3.9.13;and(4)controlledstorageoflowburnupfuelinRegionIIofthespent fuel racks as specified in Technical Specification 5.6.1.
These additional measures to preclude criticality provide an acceptable bases to continue the exemption.
The licensee's current exemption is subject to the restriction that no'more than one fuel assembly be outside an approved shipping container, storage rack, or the fuel transfer tube at any time. The licensee requests that the restriction to the existing exemption be revised. The licensee proposes to utilize the exemption provided that no more than one fuel assembly be outside an approved shipping container, storage rack, or the fuel transfer carriage at any time.
However, two foal assemblies may be in the fuel trar.sfer carriage. The bases
~for allowing two fuel assemblies in the fuel transfer carriage is the potential for accidental criticality does not exist because of geometric spacing. The geometric spacing of the transfer carriage results in a 14.25 inch center-to-center spacing between two fuel assemblies. The 14.25 inch center-to-center spacing is conservative compared to the previous 12.75 inch center-to-center spacing in the old spent fuel storage racks, which was the bases for the original exemption.
The transfer system water is also subject to boron con-centration limits, which provides additional assurance that criticality would be precluded in the event of an accident. The proposed restriction would facilitete control element assembly transfers, neutron source transfers, efficient core offloads / fuel shuffles, and provide tempora ~,'y setdwon locations when fuel handling difficulties occur in the reactor vessel.
Based upon the information provided, there is reasonable assurance that irradiated or unirradiated fuel will be subcritical due to the use of
-4 o
geometric spacing, Boraflex panels, minimum boron concentration, and controlled storage in the spent fuel pools.
In the new fuel pools, geometric spacing provides this assurance. Also, there is reasonable assurance that two fuel assemblies can be safely carried in the fuel transfer carriage. The special circumstances for granting an exemption to 10 CFR 70.24 are met because criticality is precluded with the present design configuration, Technical Specification controls, and the restriction placed upon the exemption. The re-fore, bat;d upon the revised bases stated above, the staff concludes that the licensee's request for an exemption form the requirements of 10 CFR 70.24 with respect to irradiated or unirradiated fuel in the fuel handling building is acceptable and should be granted.
This exemption is subject to the restriction that no more than one fuel assembly be outside an approved shipping container, storage rack, or the fuel transfer carriage at any time, although two fuel assemblies may be in the fuel transfer carriage.
III.
Accordingly, the Commission has determined that, pursuant to 10 CFR 70.14, an exemption is authorized by law and will not endanger life or property or the common defense and security and is otherwise in the public interest.
Accordingly, the Commission hereby grants an exemption as described in Section II above from 10 CFR 70.24, " Criticality Accident Requirements," such that the licensee is exempt from providing two criticality detectors. This exemption is subject to the restriction that no more than one fuel assembly be outside an approved shipping container, storage rack, or the fuel transfer carriage at any time, although two fuel assemblies may be in the fuel transfer carriage.
~ ~ - ~
c.-
5
+- 7 Pursuant to 10 CFR 51.32, the Commission has determined that the granting.
of this exception will have no significant impact on the quality of the human environment (55 FR 33788).
This exemption is effective upon issuance.
FOR THE NUCl. EAR REGULATORY COMMISSION l
As,~
ennis M. Cru c'h iel,
i ctor Division of Reactor Pro' ts - III, i
IV, Y and Special Projects Office of Nuclear Reactor Regulation Dated at Rockville, Maryland the 20 ' day of August
,1990.
~ *;;*[
^
~
Uf!!TED STATES NUCLEAR REGULATORY COMMISSION
_ SOUTHER!; CALIFORNIA EDIS0N COMPANY. ET AL.
SAN ONOFRE NUCLEAR GENERATING STATION.' UNIT N05. 2 AND 3-DOCKET N05. 50-361 AND 50-362 ENVIRONMENTAL ASSESSMENT AND FINDING OF NO SIGNIFICANT IMPACT The U. S. Nuclear Regulatory Comission (the Commission) is considering issuance of an exemption to Facility Operating License No. NPF-10 and Facility Operating License No. NPF-15 issued to Southern California Edision Comparty, t
San Diego Gas and Electric Comparty, the City of Riverside California, and the City of Anaheim, California (the licensee), for operation of San Onofre Nuclear Generating Station, Unit Nos. 2 and 3, located in San Diego County, i
L
'ENVIRONMENTAt. ASSESSMENT Identification of Proposed Action The proposed exemption from 10 CFR 70.24 would allow irradiatt" or 1
L unirradiated fuel assemblies to be handled and stored in the San Onofre Unit Nos. 2 and 3 fuel handling building without having two criticality monitoring systems. The exemption would be subject to the restriction that no more than one fuel assembly be outside an approved shipping container, storage rack, or the fuel transfer carriage at arty time, although two fuel assemblies may be in i
the fuel transfer carriage.
The Need for the Proposed Action The proposed exemption is required to permit refueling operations at San Onofre Units 2 and 3 to be conducted without installing the criticality detection systems specified by 10 CFR 70.24. Also, it will fccilittte cor. trol
)
)
.s t
element assembly transfers, neutron source transfers, efficient core offloads / fuel shuffled, and provide temporary setdown locations when fuel handling difficulties occur in the reactor vessel.
Environmental Impacts of the Porposed Action The proposed action would not involve a significant change in the probability or consequences of any accident previously evaluated, nor does it involve a new or different kind of accident. Consequently, any radiological releases resulting from an accident would not be significantly greater that previously determined. The proposed exemption does not otherwise affect routine radiological plant effluents. Therefore, the Commission concludes that there are no significant radiological environmental impacts associated
. with the proposed exemption. The Comission also concludes that the proposed action will not result in a significant increase in individual or chaulative occupational radiation exposure.
With regard to nonradiological impacts, the proposed exemption does not affect nonradiological plant effluents and have no other environmental impact. Therefore, the Commission concludes that there are no significant nonradiological environmental impacts associated with the proposed exemption.
R Alternative to the Proposed Action Since the Commission concluded that there are no significant environmental effects that would result from the proposed action, any L
alternatives with equal or greater environmental impacts need not be evaluated.
L The principal alternative would be to deny the requested exemption. This would not reduce environmental impacts of plant operation and would result in reduced operational flexibility.
r
- - - - - - - - - - - ~ - - - - - - - - -
- c. _
,; Alternative Use of Resources This action does not involve the use of resources not previously considered in connection with the Final Environmental Statement related to the operation of San Onofre Nuclear Generating Station, Units 2 and 3, dated April 1981 and its Errata dated June 1981.
Agencies and Persons Consulted The NRC staff reviewed the licensee's request that supports the proposed exemption,-and did not consult other agencies or persons.
FINDING OF NO SIGNIFICANT IMPACT The Comission has determined not to prepare an environmental impact statement for the proposed exemption.
Based upon the foregoing environments 1 assessment, we conclude that the proposed action will not have a significant effect on the quality of the human environment.
For further details with respect to this action, see the application for n.
exemption dated July 5, 1990 which is available for public inspection at the Comission's Public Document Room, 2120 L Street N.W., Washington, D.C. 20555, and at the Main Library, University of California, P.O. Box 19557. Irvine, California 92173.
Dated at Rockville Maryland, this 9 day of ugust
- 1990, A
FOR THE NUCLEAR REGULATORY COMMISSION t.
John T. Larkins, Acting Director Project Directorate Y Division of Reactor Projects - III, IV, Y and Special Projects Office of Nuclear Reactor Regulation
_