ML20133L737

Safety Evaluation Supporting Amend 11 to License DPR-9

ML20133L737
Person / Time
Site:	Fermi
Issue date:	01/02/1997
From:	NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS)
To:
Shared Package
ML20133L531	List: ML20133L529 ML20133L617 ML20133L737 ML20133L771
References
NUDOCS 9701220122
Download: ML20133L737 (4)

Text

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS RELATED TO AMENDMENT NO. 11 TO FACILITY OPERATING LICENSE NO. DPR-9 DETROIT EDISON COMPANY ENRICO FERMI ATOMIC POWER PLANT. UNIT 1 l DOCKET NO. 50-16

1.0 INTRODUCTION

-By letter dated August 29, 1996. Detroit Edison Company (DECO or the licensee) submitted a request for a change to the Enrico Fermi Atomic Power Plant.

Unit 1 (Fermi 1) Technical Specifications (TS) appended to Facility Operating License No. DPR-9. The requested changes would: (1) allow certain equipment and instruments to be removed from service for short periods of time to allow for maintenance, testing, inspection, modifications, and account for equipment failures: (2) reduce the frequency of environmental liquid effluent monitoring i and eliminate one raw water sampling location: (3) eliminate the requirement for moisture intrusion monitoring for the reactor building lower level and allow certain outage time for the other monitors; and (4) correction of a typographical error.

2.0 EVALUATION

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In our evaluation we considered the primary system cover gas, environmental

. surveillance, reactor building lower level moisture intrusion, and typographical error.

2.1 Primary System Cover Gas The primary system cover gas system maintains the primary system filled with carbon dioxide. The primary system cover gas system was implemented more than 20 years ago to have the residue sodium in the l system to slowly react with the carbon dioxide to form sodium carbonate. l Also, moisture intrusion from the air was prevented by having the cover gas at a pressure slightly higher than atmospheric pressure. The .

current Fermi 1 TS do not allow the licensee to remove this system from i i service for maintenance, modifications. testing, or inspections. Thus, the licensee has requested to be allowed to remove this system from service for up to 7c hours within a 30-day period.

. The licensee notes that shutting down the cover gas system would allow the cover gas pressure to decay to atmospheric after some period of time. However, as long as the pressure remains above atmospheric, moist air would not enter the primary system. Once the system pressure is 9701220122 970102?~ "#

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atmospheric, it will take additional time for the moist air to diffuse into the primary system. Finally, the licensee notes that should moist air diffuse into the primary system, it would take time for it to diffuse through the sodium carbonate that has build up over any residual sodium. Thus, the reaction would be slow and the generation hydrogen gas would be delayed. The NRC in its Safety Evaluation Report supporting issuance of Amendment 9 to the Fermi 1 license, dated April 28, 1989. found that " temporary loss of 3ressure of the cover gas will not cause significant water reactions wit 1 the residual sodium since the sodium has been mostly passivated at this time and water is not likely to enter the system because of a gas pressure loss." The staff finds this proposal acceptable based on the low probability of.

significant moisture-sodium interaction during this limited period, and ,

the benefit of permitting maintenance. modifications, testing, or inspections of the system. ,

The licensee also requested that the Fermi 1 TS be revised to allow the primary cover gas pressure alarm to be out of service for up to 30 days.

The licensee noted that the current Fermi 1 TS do not provide adequate guidance of actions to be taken, should this alarm have to be removed from service (either planned or unplanned). Thus, the licensee proposes that if the primary cover gas pressure alarm is removed from service, the licensee would verify that the system pressure is above atmospheric ,

pressure within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, and daily. thereafter, until the alarm is restored. The staff finds this proposal acceptable.  ;

i 2.2 Environmental Surveillance Environmental surveillance (sampling) establishes background and ,

determines maximum concentrations of radioactive material discharged  !

from Fermi 1 in the form of liquid effluent.

The licensee requested that the Fermi 1 TS be revised to eliminate one of its background sampling stations. The licensee's basis for this request is that Fermi 1 no longer acquires water from this location.

Fermi 1 now acquires its potable water from either Detroit or Monroe municipal water sources. The staff finds this request acceptable since both municipal potable water supply sources will continue to be sampled.

Also, the licensee requested that the Fermi 1 TS be revised to allow either grab or composite sampling. The licensee indicated that this could provide a more representative sample and the additional flexibility would allow use of samples taken for Fermi 2. The staff l finds this request acceptable.  !

1 Finally, the licensee requested that the Fermi 1 TS be revised to i suspend environmental surveillance until discharging of liquid radiological effluent discharging is resumed. The licensee noted that no liquid radiological effluent discharges have occurred from Fermi 1 in i more than 20 years. Further the Fermi 2 environmental monitoring program is capable of quantifying any significant release from Fermi 1 should one occur. The staff finds this request acceptable, based on the

3 Fermi 1 not discharging liquid radiological effluent and the ongoing environmental sampling program of Fermi 2.

i 2.3 Level Moisture Intrusion Monitors The moisture intrusion monitors provide an alarm if there is inleakage of groundwater into the lower levels of a building which may contain residual sodium. l

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The licensee has requested that the Fermi 1 TS be revised to eliminate the requirement to maintain a moisture intrusion monitor in the lower level of the reactor building. The basis for this request is the ,

industrial hazards (confined space, fall potential, and possible asbestos exposure) associated with the semi-annual surveillance. The licensee noted the this building was designed to prevent water l intrusion. The containment structure consists of a welded steel liner  !

l'to 1.25 inches thick which was coated with a corrosion inhibiting  !

coatings. The concrete beneath the containment structure was  ;

constructed using water stops between construction layers. The inside i floor is constructed of concrete. The concrete annulus, which contains  ;

containment penetrations is equipped with drains to prevent accumulation of water adjacent to the liner. Further there is no internal source of water in the containment structure. Also, the licensee noted that it has never experienced a groundwater intrusion problem in this area. The staff finds this proposal acceptable based on the non-inleakage experience in the lower level of the reactor building.

Also, the licensee requested that the Fermi 1 TS be revised to allow the other two moisture intrusion alarms to be out of service for up to 30 days. The licensee noted that the current Fermi 1 TS do not provide adequate guidance of actions to be taken should one of these alarms be removed from service (either planned or unplanned). Thus, the licensee proposes that if a moisture intrusion alarm is removed from service, the licensee will verify weekly that the affected area (s) has no abnormal accumulation of water. The staff finds this proposal acceptable.

2.4 Tvocarachical Error Technical Specification E.1. . Access, the word form is incorrect and needs to be changed to the correct word frorn. Thus, the phrase will be corrected to '... locked from the outside. .." The staff finds this change acceptable.

3.0 STATE CONSULTATION

In accordance with the Commission regulations, the Michigan State official was notified of the proposed issuance of the amendment. The State official had no comments.

-4.0 -f.NVIRONMENTALCONSIDERATION The amendment changes Fermi 1 TS with respect to the administrative procedures

f 4

or requirements. NRC 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 i significant increase in individual or cumulative occupational radiation  ;

exposure. The Commission has previously issued a proposed finding that the  !

3 amendmeat involves no significant hazards consideration, and there has been no  ;

public comment on such finding (61 FR 55029) on October 23, 1996.

l Accordingly, the 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 the amendment.

5.0 CONCLUSION

The Commission 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: (2) such activities will be conducted in compliance with the Commission regulations:

and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

Principal Contributor: S. Brown. NMSS/LLDP Date: January 2. 1997 r,