ML20127D001

Safety Evaluation Supporting Amend 70 to License DPR-54

ML20127D001
Person / Time
Site:	Rancho Seco
Issue date:	06/07/1985
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML19302G093	List: ML20127C956 ML20127C972 ML20127D001
References
NUDOCS 8506240090
Download: ML20127D001 (5)

Text

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g UNITED STATES NUC' LEAR REGULATORY COMMISSION

r. 8 WASMNGTON, D. C. 20555

' \*****J: SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION

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i SUPPORTING AMENDMENT NO.70 TO FACILITY OPERATING LICENSE NO.'DPR-54

! SACRAMENTO MUNICIPAL UTILITY DISTRICT i

RANCHO SECO NUCLEAR GENERATING STATION

, DOCKET NO. 50-312

! INTRODUCTION

, By letter dated February 14, 1985, as revised May 6, 1985, the Sacramento Municipal Utility District (the licensee) submitted an application to amend Facility Operating License No. DPR-54 for the Rancho Seco Nuclear Generating Station. The amendment would revise the Technical Specifications to-incorporate design changes to the Control Room / Technical Support Center (TSC)

Emergency Filtering System and the Air Supply System which are subsystems of the new Control Room /TSC Emergency Heating, Ventilating and Air Conditioning (HVAC) System.

BACKGROUND To satisfy the habitability requirements of NUREG-0737, Item III.D.3.4, the Control Room Emergency HVAC System was modified from a single train system into a two-loop redundant full-flow system. In addition, the Control Room i Emergency HVAC System was expanded to include the Emergency HVAC requirements for the TSC. The new Control Room /TSC Emergency HVAC System is designed to satisfy the habitability requirements of both the Control Room and the TSC.

As a separate licensing action, we reviewed the licensee's proposed modifications and found them acceptable.

EVALUATION The licensee's application dated February 14, 1985, would revise the Technical Specifications to (1) change the Limiting Condition for Operation (LCO) for i

the Control Room /TSC Emergency Filtering System to reflect the new design, (2) revise the surveillance testing of the Air Supply System to reflect new design flow rates and Control Room /TSC positive pressure requirements, and (3) revise surveillance testing of the filtering system to reflect proposed 4

reduced removal efficiencies for testing of the charcoal and HEPA filters and 1 to reflect new design flow rates.

The current LCO for the Emergency Control Room Filtering System requires that if the single train filtering system is inoperable, that the system be restored to operable status within 3.5 days or be in at least hot standby within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in cold shutdown within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

The proposed new Technical Specifications require the same action for the i

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i modified Emergency Control Room /TSC Filtering System if both trains are

, inoperable, i.e., no emergency filtration available. Therefore, for the i case where there is no emergency filtration available, the proposed Technical Specifications are the same as the current Technical Specifications. For the i case where a single train is inoperable, the proposed Technical Specifications i require that with one Control Room /TSC Emergency Filtering System train

inoperable, the system must be restored to operable status within 7 days or be i in at least hot standby within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> or in cold shutdown within the i following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. This is the same as the Standard Technical Specification i requirement for a single train inoperable. Therefore, we find the proposed LCO 1

Technical Specifications for the Control Room /TSC Emergency Filtering System '

j acceptable (Item 1).

! As noted above, as another licensing action, we reviewed the proposed j modifications to the Control Room /TSC HVAC System. From our review, we have t

concluded that for the proposed design modifications there will be no j significant radiological impact as compared to the present design, and it f will not affect the exposure limit of General Design Criterion (GDC) 19 and j Standard Review Plan (SRP) 6.4. In addition, we have also concluded that the i positions of Regulatory Guide 1.75 and 1.95 and SRP Section 6.4, as they

! relate to toxic gas protection of the operators, will still be met. Since j the Control Room /TSC Emergency Filtering System and the Air Supply System are 1

subsystems of the Control Room /HVAC System, we conclude that with the j proposed Control Room /TSC Emergency HVAC System modifications and appropriate l Technical Specifications for surveillance testing of the Control Room /TSC j Emergency Filtering System and the Air Supply System (Items 2 and 3 above),

i occupancy in the Control Room can be maintained under design basis accident

, conditions without exceeding GDC-19 for the duration of the accident. We have

{ also found the surveillance testing for these systems proposed by the licensee 1 acceptable, except for the specified removal efficiencies for testing charcoal

{ and HEPA filters. The licensee proposed removal efficiencies that are less i than those in the current Technical Specifications. Subsequently, by letter i

dated May 6, 1985, the licensee revised the February 14, 1985, application to i delete the proposed change of the reduced charcoal and HEPA filter testing (i.e., so that the current Technical Specifications remain unchanged).

! We independently evaluated the modified Control Room /TSC HVAC System to .

i determine if GDC-19 is met for the radioactive iodine removal efficiency for  !

! filtration of 99% proposed by the licensee. This efficiency would require

! surveillance testing of the charcoal filters consistent with the requirements l of Regulatory Guide 1.52, Revision 2. These requirements are more stringent ,

than are presently required by the existing Rancho Seco Technical Specifications for charcoal filters. Because ongoing source term research work indicates iodine releases from a core melt accident are not expected to

.; be instantaneous and may be primarily in a particulate form, cessium iodide issues relating to iodine removal are subject to future reevaluation. With j this consideration, it is judged that the more stringent' filter testing I

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requirement that otherwise would be applicable to this new filtration system should not be required. Instead, the existing charcoal and HEPA filter testing requirements specified in the current Technical Specifications will be sufficient for the interim pending an NRC staff decision on source terms and their overall effect on safety systems. Therefore, we conclude that the Technical Specification changes proposed in the February 14, 1985, application, as revised by the May 6,1985, letter are acceptable.

EMERGENCY CIRCtfMSTANCES The following reasons describe the emergency circumstances as to why regular notification procedures are not required for this amendment:

1. NRC regulation 10 CFR 50.91 describes the procedures that will be followed on applications received after May 6, 1983, requesting license amendment. These procedures require that, in addition to other requirements, a 30-day coment period will be provided to allow for public coment on the Comission's proposed no significant hazards consideration detemination. The latest revision to the proposed amendment required to resolve a technical problem was received by the Comission on May 10, 1985.

Therefere an expedited notice of such detemination related to this amendment was published in the Federal Register on May 16, 1985, and the 30-day coment period expires on June 17, 1985.

2. The licenset, in its May 29, 1985, letter stated that the Rancho Seco plant was shutdown for a scheduled 90-day outage. The licensee further stated that due to exceptional perfomance of plant personnel, a very effective scheduling program, and the ability to resolve problems quickly, the outage schedule progressed ahead of the planned outage.

The licensee now expects to heatup the plant on June 5 with criticality on June 7. This is about one week ahead of the schedule planned prior to the shutdown on March 15, 1985.

In addition, the licensee also stated that because of the impending sumer heat load and the high cost of oil generated capacity, Rancho Seco should l be put on-line as soon as possible.

The Commission has detemined that emergency circumstances exist in that swift action is necessary to avoid a delay in startup not related to safety and finds that for the reasons stated above, these circumstances caused the outage to be completed earlier than scheduled.

In connection with requests indicating an emergency, the Comission expects its licensees to apply for license amendments in a timely fashion. However, with this consideration in mind, it has been determined that a circumstance has arisen where the licensee and the Comission must act quickly, and the licensee has made a good effort to make a timely application.

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i FINAL NO SIGNIFICANT HAZARDS CONSIDERATION DETERMINATION The Connission's regulations in 10 CFR 50.92 state that the Connission may make a final determination that a license amendment involves no significant hazards considerations if operation of the facility in accordance with the ,

amendment would not:

(1) Involve a significant increase in the probability or consequences of an accident previously evaluated; or (2) Create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) Involve a significant reduction in a margin of safety.

The information in this Safety Evaluation provides the basis for evaluating this license amendment against these criteria. The request for amendment to the Technical Specifications incorporates design changes made to the Control Room HVAC System to satisfy the habitability requirements of NUREG-0737, Item III.D.3.4 The revised Technical Specifications are based on the modified design of the HVAC System and fall within the acceptance criteria. Since the requested change does not affect the plant's design basis or plant operating i

conditions, we conclude that:

d' (1) Operation of the facility in accordance with the amendment would not significantly increase the probability or consequences of an accident previously evaluated.

.i (2) Operation of the facility in accordance with the amendment would not

'l create the possibility of a new or different kind of accident from any accident previously evaluated.

(3) Operation of the facility in accordance with the amendment would not involve a significant reduction in a margin of safety.

Accordingly, we conclude that the amendment to Facility Operating License DPR-54 to support operation of Rancho Seco Nuclear Generating station at full rated power during the upcoming Cycle 7 involves no significant hazards considerations.

STATE CONSULTATION 1

In accordance with the Comission's regulations, consultation was held with the State of California by telephone. The State expressed no concern either from the standpoint of safety or of our no significant hazards consideration determination, l

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ENVIRONMENTAL CONSIDERATION  ;

This amendment involves a change in the installation or use of'a facility component located within the restricted area as defined in 10 CFR Part 20 and changes a surveillance requirement. We have 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 made a final no significant hazards consideration finding with respect to this amendment. Accordingly, this amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of this amendment.

CONCLUSION We have concluded, based on the considerations discussed above, that:

(1) there is reasonable assurance that the health and safety of the will not be endangered by operation in the proposed manner, andsuch (2) public 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 bralth and safety of the public.

Dated: June 7, 1985 Principal Contributors: F. Akstulewicz, R. Fell, and S. Miner l

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