ML20127E451
| ML20127E451 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 06/06/1985 |
| From: | Musolf D NORTHERN STATES POWER CO. |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| RTR-REGGD-01.097, RTR-REGGD-1.097 NUDOCS 8506240553 | |
| Download: ML20127E451 (3) | |
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.#f-Northem States Power Company 414 Nicotet Mad Minneapoks. %nnesota 55401 Teechone 1612) 330 5500 June 6, 1985 Director Office of Nuclear Reactor Regulation US Nuclear Regulatory Commission Washington, DC 20555 Prairie Island Nuclear Generating Plant Docket Nos. 50-282 License Nos. DPR-42 50-306 DPR-60 Additional Information Related to Conformance Con formance with Regulatory Guide 1.97 Revision 2 The purpose of this letter is to provide, for the information of the NRC Staff, additonal information related to modifications plan-ned at the Prairie Island Nuclear Generating Plant to conform to the requirements of Regulatory Guide 1.97, Revision 2, "Instrumen-tation for Light-Water-Cooled Nuclear Power Plants to Assess Plant and Environs Conditions During and Following an Accident."
This information supplements information provided in our letter of January 18, 1985 and in a telephone conference call with our Pro-Ject Manager in the Division of Licensing earlier this year.
Pressurizer Heater Power Monitoring. Item 7 A monitoring system for pressurizer heaters supplied with essential power will be installed.
The monitor will consist of a sensor, signal conditional, and a computer input device.
Pressurizer heater power will be available as a demand display on the ERF computer system.
This modification will be com-pleted in Unit 1 prior to Cycle 12 operation and in Unit 2 prior to Cycle 11 operation.
Steam Generator Wide Range Level. Item 9 Redundant wide range steam generator level instrumentation currently exists for each steam generator at Prairie Island.
Only one channel is environmentally qualified, however.
We will replace the non-qualified instrumentation with fully qualified equipment. This modification will be completed in Unit 1 prior to Cycle 12 operation and in Unit 2 prior to Cycle 11 operation.
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p:o-Northem States Power Company Director of NRR June 6, 1985 Page 2 Containment Spray Flow. Item 13 Containment Sump Water Temperature. Item 13 As indicated during discussions with the NRC Staff, these two requirements may be met using RHR heat exchanger temperature instrumentation.
Temperature indication will be added to the RHR heat exchanger inlets.
These sensors will be qualified appropriately for their location.
The work will be completed prior to startup of Cycle 12 for Unit I and prior to startup of Cyle 11 for Unit 2.
Environmental Qualification Requirments of Regulatory Guide 1.97. Revision 2.
and 10 CFR Section 50.49 A number of exceptions were taken in our submittal of Septem-ber 15, 1983 to the environmental qualification requirements of Regulatory Guide 1.97, Revision 2.
Subsequently, the Com-mission issued 10 CFR Section 50.49 which cited Regulatory Guide 1.97, Revision 2, as specific guidance to be used in environmental qualification of post accident monitoring in-strumentation.
The majority of instruments for which we took exception to the Regulatory Guide 1.97, Revision 2, environmental qualification requirements are in a mild environment for the accident in which whey would be utilized.
No further action is required in the case of these instruments.
In the case of accumulator tank level, this instrument in not in a mild environment.
In addition, the range of the instal-led instrumentation does not meet the Regulatory Guide requirements.
As noted in item (6) of our January 18, 1985 letter, we believe accumulator level instrumentation is not required for post accident monitoring since other indicators of proper accumulator performance are provided in the plant design.
Existing containment air temperature instrumentation is not environmentally qualified and is not located in a mild environment.
We will upgrade containment air temperuture sensors and display them on the ERF computer system.
Comple-tion of this upgrade will be completed in Unit 1 prior to Cycle 12 Operation in and Unit 2 prior to Cycle 11 operation.
Please contact us if you have any questions related to the informa-tion we have provided.
As noted above, we have commited to com-plete additional plant modifications related to Regulatory Guide 1.97 1
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Director of NRR Northem States Power Company June 6, 1985 Page 3 compliance.
We will submit, in separate correspondence, a request for a change in the schedule specified in the Commission's Confir-ming Order dated June 14, 1984 to accomodate this additional work.
Detailed information to support the schedule we have described for these additional modifications will be supplied in this letter.
D d As David Musolf Manager - Nuclear pport Services c: Regional Administrator III, NRC Resident Inspector, NRC G Charnoff t
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