ML020250352
| ML020250352 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 02/04/2002 |
| From: | Gratton C NRC/NRR/DLPM/LPD1 |
| To: | Clifford J NRC/NRR/DLPM/LPD1 |
| Gratton C, NRR/DLPM 415-1055 | |
| References | |
| TAC MB2192, TAC MB2193 MHI-5075, Rev 5, NRR-106 | |
| Download: ML020250352 (3) | |
Text
February 4, 2002 MEMORANDUM TO: James W. Clifford, Chief, Section 2 Project Directorate 1 Division of Licensing Project Management Office of Nuclear Reactor Regulation FROM:
Christopher Gratton, Sr. Project Manager, Section 2
/RA/
Project Directorate 1 Division of Licensing Project Management Office of Nuclear Reactor Regulation
SUBJECT:
LIMERICK GENERATING STATION (LGS), UNITS 1 AND 2, EMAIL TRANSMISSION, ISSUES TO BE DISCUSSED IN AN UPCOMING CONFERENCE CALL (TAC NOS. MB2192 and MB2193)
The attached information was e-mailed on January 22, 2002, to Mr. David Helker of Exelon Generation Company, LLC (the licensee). This information was transmitted to facilitate an upcoming conference call in order to clarify the licensees submittal dated June 1, 2001. In the submittal, the licensee requested a revision to the LGS Units 1 and 2 Technical Specifications to revise Limiting Condition for Operation 3.6.1.7 concerning drywell average air temperature. This memorandum and the attached questions do not convey or represent a Nuclear Regulatory Commission staff position regarding the licensees request.
Docket Nos. 50-352 and 50-353
Attachment:
Issues for Discussion in Upcoming Telephone Conference CONTACT: Christopher Gratton, NRR (301) 415-1055
ML020250352 OFFICE PM/PD1-2 LA/PD1-2 NAME CGratton MOBrien DATE 2-4-02 2/4/02
Issues for Discussion in Upcoming Telephone Conference Regarding Exelon License Request No. LG 99-01766 Limerick Generating Station Drywell Average Air Temperature
- 1) Please explain the basis for the 145F annual average temperature and the 150F maximum temperature with regard to the equipment qualification program. Specifically, what does the difference between these two temperatures intend to account for, and what conservatisms, if any, are inherent in the 145F annual average temperature limit?
- 2) On the second page of the submittal, third paragraph from the bottom, the topic sentence reads: UFSAR Section 3.11 discusses the environmental design of electrical equipment. The paragraph then proceeds to describe the treatment of qualified equipment. It is not clear to the staff whether the use of the word equipment in this paragraph applies strictly to electrical equipment (based upon the implication of the paragraphs topic sentence) or all qualified equipment (e.g., including environmentally qualified mechanical components). Please clarify the use of the word equipment.
- 3) Please be prepared to discuss what mechanical component-types in the drywell are most temperature-sensitive and provide examples of their qualified lifetimes based on a 145F annual average temperature. Highlight any changes to qualified lifetimes.
- 4) What is the instrument uncertainty associated with the drywell temperature indications, and how does the licensees proposal account for the uncertaintys affect on the average drywell air temperature calculation, considering both drywell equipment qualification and the analysis of peak drywell pressure and temperature?
- 5) The proposed increase to the TS-allowable limit for drywell average air temperature would eliminate the current 10F margin between it and the annual average temperature used for the equipment qualification program. The staff wishes to verify that this margin does not require the licensee to modify TS SR 4.6.1.7, which provides requirements for the calculation of drywell average air temperature. Has the licensee considered whether the current method of calculating drywell average air temperature (i.e., using at least one temperature reading from each drywell elevation) remains adequate for equipment qualification purposes, considering that this margin will be eliminated? In essence, is the azimuthal drywell temperature variance small enough such that a single reading at each drywell elevation would continue to provide an average air temperature which is adequately conservative for equipment qualification purposes if the proposed change were implemented? On what basis does the licensee have this assurance?
Attachment