ML20206H177

Safety Evaluation Supporting Amend 20 to License DPR-7

ML20206H177
Person / Time
Site:	Humboldt Bay
Issue date:	06/16/1986
From:	Office of Nuclear Reactor Regulation
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ML20206H151	List: ML20206H147 ML20206H165 ML20206H177
References
NUDOCS 8606250552
Download: ML20206H177 (2)

Text

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k UNITED STATES

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j NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555

\...+/ SAFET) EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT N0. 20 TO FACILITY OPERATING LICENSE NO. DPR-7 PACIFIC GAS AND ELECTRIC COMPANY HUMBOLDT BAY POWER PLANT, UNIT NO. 3 DOCKET NO. 50-133

1.0 INTRODUCTION

By letter dated December 16, 1983, as supplemented March 7,1986, Pacific Gas and Electric Company (the licensee) proposed to delete License Condition E.2.e which requires the reinstatement and operation of a microseismic monitoring network to gather data at the Humboldt Bay Power Plant, Unit No. 3 (the facility). License Condition E.2.e was established by the

" Order for Modification of License" issued by the Comission on May 21, 1976. This condition was part of the seismic design upgrading program required to be complete prior to a return of the facility to power operation following the 1976 refueling outage.

On July 2,1976 the facility was shut down for refueling and the required seismic modifications. In 1983, the licensee concluded that the seismic modifications and the modifications necessary to comply with requirements '

imposed after the accident at the TMI Unit 2 were uneconomical and decided to decommission the facility.

2.0 EVALUATION The seismic monitoring system required by License Condition E.2.e is a high-gain, 16 station, seismogranhic network that was installed in the local area around Humboldt Bay Unit 3. The system has been used for data gathering for the licensee's studies of local faulting and earthquake potential near the facility. These studies were needed for justification of a restart of the facility and are not now needed for any purpose, as the facility is permanently shut down.

All fuel has now been removed from the reactor vessel and placed in the spent fuel storage pool. The reactor cooling system and associated tanks and pipes have been drained and sealed. The suppression pool, below the reactor vessel, has been drained. Ion exchange systems were used to remove chemicals and radionuclides from the waste water prior to its discharge. The only water containing radionuclides that remains on site is the water in the spent fuel pool, its associated systems and in the radwaste tanks.

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i We have reviewed the potential for accidents at the shutdown facility caused by seismic events and nave determined that any damage to the spent fuel pool or radwaste tanks by a seismic event would result in radioactive releases that are a small fraction of EPA Protective Action Guides. Cor evaluation is discussed in NUREG-1166, " Draft Environmental Statement for decommissioning Humboldt Bay Power Plant, Unit No. 3," April 1986.

Therefore, the staff has determined that there is minimal safety benefit in continuing to operate the seismic monitoring network at the facility.

3.0 ENVIRONMENTAL CONSIDERATION

This amendment involves a change in surveillance requirements for gathering seismic information. The staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that this amendment involves no significant hazards consideration and there has been no public comment on such finding. Accordingly, this amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 551.22(c)(9). Pursuant to 10 CFR 551.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of this amendment.

4.0 CONCLUSION

The staff has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner; and (2) such activities will be conducted in compliance with the '

Commission's regulations, and the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.

Dated: June 16, 1986 Principal Contributor: Peter B. Erickson

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