ML20052B769
| ML20052B769 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 04/23/1982 |
| From: | Mayer L NORTHERN STATES POWER CO. |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TASK-2.B.1, TASK-TM NUDOCS 8205030547 | |
| Download: ML20052B769 (2) | |
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Northern States Power Company 414 thcollet Mall Minneapohs, Minnesota 55401 Telephone (612) 330-5500
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April 23, 1982 g
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Of fice of Nuclear Reactor Regulation U S Nuclear Regulatory Commission RE Washington, DC 20555 4V i'
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PRAIRIE ISLAND NUCLEAR GENERATING PLANT Docket Nos. 50-282 License Nos. DPR-42 50-306 DPR-60 Implementation of Interim Requirements Related to Hydrogen Control, Paragraph (c) of Section 50.44 of 10 CFR Part 50 was revised by a final rule published in the Federal Register on December 2, 1981. The rule became effective on January 4, 1982 and requires:
- a. The installation of either internal recombiners or the capability to install external recombiners following the start of an accident.
- h. High point vents for the reactor coolant system, vessel head, and for other systems required to maintain adequate core cooling if the accumulation of noncondensible gases would cause the loss of function of these systems.
The rule requires completion of these modifications by the end of the first scheduled refueling outage beginning after July 5, 1982 which is of suffi-cient duration to complete the work.
The purpose of this letter is to inform the Commission of our plans and schedule for completing these modifications and of the possibility that a request for exemption from the required completion schedule may be required due to delays in delivery of components.
Recombiner Installation We have investigated the internal and external recombiner options and have determined that the internal recombiner system offers advantages in terms of engineering, operational considerations, and ease of installation at Prairie Island. We are proceeding with engineering and procurement to install Westinghouse Model B recombiners. Redundant recombiners will be installed in each containment vessel.
82050305y N,
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t NORTHERN CTATED POWER COMPANY l
Director of NRR April 23, 1982
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Page 2 Outages scheduled af ter July 5,1982 of sufficient duration to l
complete this installation are-i November, 1982 refueling outage Unit 1 Unit 2 - July, 1983 refueling outage We are now directing our efforts to complete the Unit 1 installation t
during the November, 1982 refueling outage.
It is not certain at this time, however, that all equipment, including new containment electrical penetrations, can be delivered in time to complete installation during this outage. We anticipate no difficulty in completing the Unit 2 installation during the July, 1983 refueling outage.
If it appears that installation in Unit 1 cannot be completed as planned j
during the. November, 1982 refueling outage, a request for exemption from i
the schedule requirements of 10 CFR Part 50, Section 50.44(c)(3)(ii),
will be submitted to defer the work until the next refueling outage of Unit 1.
High Point Vents
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Installation of a high point vent system consisting of six remotely operated solenoid valves which can vent either the reactor head or pressurizer steam space to the pressurizer relief tank or directly to containment was described in our letter dated July 6, 1981. This installation satisfies the requirements of NUREG-0737, Item II.B.1.
Installation in Unit 1 is complete, however the system remains isolated pending NRC authorization to use the vents.
The Unit 2 installation is complete with the exception of control board wiring. The system will be completed during the next Unit 2 refueling outage now scheduled for June, 1982.
We anticipate no difficulty, therefore, in completing this modifi-l cation in both units by the date specified in the rule, j
Please contact us if you have any questions related to our plans and f
schedule for implementing the requirements of 10 CFR Part 150, Section 50.44(c) at the Prairie Island Nuclear Generating Plant.
. t$2 L 0. Mayer, PE Manager of Nuclear Support Services LOM/DKM/bd l
cc: -Regional Administrator-III, NRC Resident Inspector, NRC
-NRR Project Manager, NRC G Charnoff i
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