ML20236A620
| ML20236A620 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 10/15/1987 |
| From: | Hood D Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20236A623 | List: |
| References | |
| NUDOCS 8710220441 | |
| Download: ML20236A620 (6) | |
Text
- - _ _. _ _ - _
o 7590-01 UNITED STATES NUCLEAR REGULATORY COMMISSION DUKE POWER COMPANY, ET AL.
DOCKET N05. 50-413 AND 50-414 ENVIRONMENTAL ASSESSMENT AND FINDING OF N0 SIGNIFICANT IMPACT The U.S. Nuclear Regulatory Cormiission (the Commissions is considering issuance of amendments to the Duke Power Company, et al., (the licensee) for the Catawba Nuclear Station, Units 1 and 2, located in York County, South Carolina.
ENVIRONMENTAL ASSESSMENT Identification of Proposed Action: The proposed amendments would change the Technical Specifications to provide for operation up to full power with l
The UHI System was the Upper Head Injection Accumulator (UHI) System removed.
designed to enhance core cooling during the blowdown phase of a loss-of-coolant accident (LOCA). Similar changes have previously been approved by the Connission for McGuire Nuclear Station, Units 1 and 2 (Amendment Nos. 57 and 38 for Units 1 and 2, respectively, issued May 13,1986).
Other changes associated with UH1 removal would also be made to These include deletion of Technical appropriate Technical Specifications.
Specifications requiring UHI system maintenance, surveillance, and leakage verification and modification of Technical Specifications to reflect deletion of UHI related containment penetrations and associated conductor overcurrent protective devices, containment isolation valves, and system piping snubbers.
8710220441 871020 DR ADOCK 050 3
D 4
i 5
-The oroposed Technical Specifications also reflect changes to'the ECCS cold leg injection accumulators to. increase the operable range limits of the nitrogen gas cover-pressure (from 385 and 481 psig to 585 and 678 psig), and to decrease the operable range limits of their water volume (from '7853 and 8171 gallons to 7704 and 8004 gallons).
The changes to the'ECCS cold leg injection accumulators would also be accompanied by appropriate modifications to instrumentation alarm functions and, procedures, and by replacement of flow restricting orifices in their dis-charge piping with orifices of smaller diameter. However, these accompanying changes do not involve a change to the Technical Specifications.
The proposed action is in accordance with the licensee's letters dated June 12, 1987, and supplemented June 23 and August 12, 1987.
The Need for the Proposed Action: The licensee has requested this action because the UHI system has been found to cause frequent maintenance problems and operational delays. Filling and venting requirements of the UH1 System add about 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> to a startup from cold shutdown conditions. The system contributes to occupational radiation exposure during normal operation (i.e.,
during surveillance and maintenance) and during refueling outages requiring removal or reconnection of injection piping to the reactor vessel upper head.
The continuing operational difficulties and radiological exposures associated with the UHI system would be eliminated upon completion of system removal.
Environmental Impacts of the Proposed Action A.
Plant Radiological Releases The VH1 system performs no function during normal operation but serves to Therefore, no adverse change in plant mitigate accidents after they occur.
t;.^
F I '
El'
)
radiological or non-radiological releases would occur.for normal operation of the plant with the UHI system isolated or removed.
By letter dated June 12, 1987 and supplemented June 23,1987, the licensee B
provided safety analyses for LOCA and non-LOCA transients for the planned UHI The Comission has removal using approved analytical models and methodology.
reviewed these analyses and finds that the potential radiological and non-radiological releases for accidents and transients would not be increased.
Accordingly, Comission findings in the Final Environmental Statement
.Related to Operation of Catawba Nuclear Station, Units 1 and 2, dated January i
1983 (NUREG-0921) regarding radiological and non-radiological releases from the plant during nonnal operation or after accidents are not adversely altered by this' action.
B.
Occupational Radiological Aspects of UHI Removal By letter dated June.12 and August 12, 1987, the licensee described the 4
construction changes and activities associated with UHI removal. The principal tasks involve (1) replacing cold leg accumulator flow element orifice plates, (2) cutting and capping UHI penetrations to the reactor vessel, (3) capoing various VH1 piping interfaces with other systems, (4) removing UHI piping, valves, support / restraints and instrumentation, (5)cuttingandcappingcon-tainment penetrations, and (6) changing the level and pressure on the cold leg The dose incurred from task performance (80 person-rem per unit) accumulators.
is a small fraction of the 1986 annual average PWR dose of 392 person-rem per unit.
4 t
/
l The Conmission has evaluated the radiological aspects of the proposed changes against the criteria of Chapter 12 of the Standard Review Plan (NUREG-0800) and Regulatory Guide 8.8, "Information Relevant to Ensuring that Occupational Radiation Exposures at Nuclear Power Stations will be as low as is Reasonably Achievable," and has concluded that the radiological aspects of UHI removal have been fully considered, and that the radiation protection measures planned for the tasks are acceptable to protect the workers, and will result in doses that are as low as is reasonably achievable.
C.
Waste Removal of the UHI related components and associated tasks would generate contaminated components for each Catawba unit, mostly comprised of various-diameter pipes, valves, hangers, and thermal sleeves. An estimate of the curies of beta and gamma radioactivity contained in the UHI components to be
~
removed is 5.3 curies per unit. This estimated activity represents less than 5.1% of the total activity shipped from Catawba Nuclear Station in solid waste during the first six months of 1987.
Disposal and shipment of radio-active materials will be performed in accordance with applicable regulatory requirements.
D.
CONCLUSION Plant radiological and non-radiological releases during normal operation or after an accident will not be increased by the proposed action. Disposal of system components would add only a small fraction to the radioactivity nonnally shipped from the site in solid waste.
The radiological exposure of construction workers during UHI removal will be as low as is reasonably achievable, and will be less than the dose which would, otherwise, result to personnel observing and maintaining the UHI system for the remainder of plant
rm
. O.
. :q.
~
-5'-
+
life. Accordingly. we conclude-that this proposed action would result in no significant adverse environmental impact.
Alternative'to the Proposed Actions:
Since we have concluded that the environmental effects of the proposed action are negligible, any alternatives with-equal or greater environmental impact need not be evaluated.
.The principal alternative would be to deny the requested amendments.
That alternative, in effect, is the same as the "no action" alternative.
J Neither alternative would reduce environmental impacts of plant operation but would result in increased personnel radiation exposure during plant life.
Alternative Use of Resources: This action does not involve the use of resources not previously considered in connection with the Nuclear Regulatory Coninission's Final Environmental Statement dated January 1983 (NUREG-0921) related to this facility, i
Agencies and Persons Consulted: The NRC staff reviewed the licensee's
-requests of June 12, 1987, as supplemented June 23 and August 12, 1987. The NRC staff did not consult other agencies or persons.
Finding of Nc, Significant Impact:
The Coninission has detennined not to prepare an environmental impact statement for the proposed license amendments.
Based upon this environmental 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 request for amendment dated June 12, 1987, and its supplements dated June 23 and August 12, 1987; and the Final Environmental Statement related to operation of Catawba Nuclear Station, Units 1 and 2 (NUREG-0921) dated January 1983, which are
}
- - 1 I
l' available for'public inspection at the Commission's Public' Document Room, 1717 LH Street, N.W., Washington, D.C., and the York County Library,138 East Black Street, Rock. Hill', South Carolina 29730.
Dated at Bethesda, Maryland this 1 5 ay of O / 7 T( 7..
/
FOR THE NUCLEAR REGULATORY COMMISSION Mu H c o Darl S. Hoo, Acting Director Project Directorate 11-3 Division of Reactor Projects I/II 1
l i
l I
--___m._