ML20199C090
| ML20199C090 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 11/12/1997 |
| From: | Collins S NRC (Affiliation Not Assigned) |
| To: | PACIFIC GAS & ELECTRIC CO. |
| Shared Package | |
| ML20199C095 | List: |
| References | |
| NUDOCS 9711190216 | |
| Download: ML20199C090 (5) | |
Text
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7590-01-P UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION In the Matter of
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PACIFIC GAS AND ELECTRIC COMPANY
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Docket Nos. 50-275
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and 50-323
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(Diablo Canyon Power Plant. Units 1 and 2)
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EXEMPTION 1.
The Pacific Gas and Electric Company, et al. (the licensee) is the holder of Facility Operating License Nos. DPR-80 and DPR-82 which authorize operation of the Diablo Canyon Power Plant (DCPP) Units 1 and 2.
The licenses provide, among other things, that the licensee is subject to all rules, regulations, and orders of the Connission now or hereafter in effect.
The facility consists of two pressurized-water reactors at the licensee's site located in Sar. Luis Obispo County California.
II.
Section 70.24 of Title 10 of the CODE OF FEDERAL REGULATIONS.
" Criticality Accident Requirements." requires that each licensee authorized to possess special nuclear material (SNM) shall maintain a criticality accident
. monitoring system in each area where such material is handled, used, or stored. Subsections (a)(1) and (a)(2) of 10 CFR 70.24 specify detection and sensitiv'ity requirements that these monitors must meet. Subsect;an (a)(1) also specifies that all areas subject to criticality accident monitoring must
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be covered by two detectors. Subsection (a)(3) of 10 CFR 70.24 requires licensees to maintain emergency procedures for each area in which this licensed SNM is handled, used, or stored and provides that (1) the procedures ensure that all personnel withdraw to an area of safety upon the sounding of a criticality accident monitor alarm (2) the procedures must include drills-to familiarize personnel with the evacuation plan, and (3) the procedures designate responsible individuals for determining the cause of the alarm and placement of radiation survey instruments in accessible locations for use in such an emergency.
Subsection (b)(1) of 10 CFR 70.24 requires licensees to have a means to identify quickly personnel who have received a dose of 10 rads or more. Subsection (b)(2) of 10 CFR 70.24 requires licensees to mai'itain personnel decontamination facilities, to maintain arrangements for a physician and other medical personnel qualified to handle radiation emergencies, and to maintain arrangements for the transportation of contaminated individuals to treatment facilities outside the site boundary.
Paragraph (c) of 10 CFR 70.24 exempts Part 50 licensees from the requirements of paragraph (b) of 10 CFR 70.24 for SNM used or to be used in the reactor.
Paragraph (d) of 10 CFR 70.24 states that any licensee who believes that there is good cause why he should be granted an exemption from all or part of 10 CFR 70.24 may apply to the Commission for such an exemption and sh611 specify the reasons for the relief-requested.
III.
The SNM that could be assembled into a critical mass at DCPP. Units 1 and 2..is in the form of nuclear fuel: the quantity of SNM other than fuel that is. stored on site in any given locction is small enough to preclude achieving a critical mass. The Commission's technical staff has evaluated the
3-possibility of an inadvertent criticality of the nuclear fuel at DCPP, Units 1 and 2. and has determined that it is extremely unlikely for such an accident to occur if the licensee meets the following seven criteria:
1.
Only one fuel assembly is allowed out of a t, hipping cask or storage rack at one time.
2.
The k-effective does not exceed 0.95, at a 95% probability. 95%
confidenc'e level in the event that the fresh fuel storage racks arr.-
filled with fuel )f the maximum permissible U-235 enrichment and flooded with pure water.
3.
If optimum moderation occurs at low moderator density, then the k-effective does not exceed 0.98 at a 95% probability, 95% confidence level in the event that the fresh fuel storage racks are filled with fuel of the maximum permissible U 235 enrichment and flooded with a moderator at the density corresponding to optimum moderation.
4.
The k-effective does not exceed 0.95, at a 95% probability, 95%
confidence level in the event that the spent fe.;l storage racks are filled with fuel of the maximum permissible U-235 enrichment and flooded with pure water.
5.
The quantity of forms of special nuclear material, other than nuclear fuel, that are stored on site in any given area is less than the quantity necessary for a critical mass.
6.
Radiation monitors, as required by General Design Criterion 63, are provided in fuel storage and handling areas to detect excessive radiation levels ano to initiate appropriate safety actions.
7.
The 7aximum nominal U-235 enrichment is limited to 5.0 weight percent.
' By letter dated April 3, 1997, and supplemental letter dated August 4, 1997. the licensee requested an exemption from 10 CFR 70.24.
In this request the licensee addressed the'seven criteria given above. The Comission's technical staff has reviewed the licensee's submittals and has determined that DCPP. Units 1 and 2. meets the criteria for prevention of inadvertent criticality: therefore, the staff has determined that it is extremely unlikely for an inadvertent criticality to occur in SNM handling or storage areas at DCPP Units 1 and 2.
The purpose of the criticality monitors required by 10 CFR 70.24 is to ensure that if a criticality were to occur during the handling of SNM.
personnel would be alerted to that fEct ano would take appropriate action.
The staff has Getermined that it is extremely unlikely that such an accident could occur: furthermore, the licensee has radiation monitors, as required by General Design Criterion 63, in fuel storage and handling areas.
These monitors will alert personnel to excessiv radiation levels and allo.4 them to initiate appropriate safety actions.
The low probability of an inadvertent criticality, together with the licensee's adherence to General Design Criterion 63, constitutes good cause for granting an exemption to the requirements of 10 CFR 70.24.
IV.
The Commissicn has determined that, pursuant to 10 CFR 70.14. this exemption is authorized by law, will not endanger life or property or the common defense and security, and is otherwise in the public interest.
Therefore, the Commission hereby grants Pacific Gas and Electric Company an exemption from the requirements of 10 CFR 70.24.
-j 5-Pursuant to 10 CFR 51.32. the Comission has determined that the granting of this exemption will have no significant impact on the environi,' ant (62 FR 59907).
This exemption is effective upon issuance.
FOR THE NUCLEAR REGULATORY COMMISSION a
Director ffice of Nuclear Reactor Regulation Dated at Rockville. Maryland, this 12th day of November 1997 p
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