ML20072B005
| ML20072B005 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 01/18/1983 |
| From: | Lundvall A BALTIMORE GAS & ELECTRIC CO. |
| To: | Eisenhut D Office of Nuclear Reactor Regulation |
| References | |
| GL-82-32, NUDOCS 8301250102 | |
| Download: ML20072B005 (2) | |
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BALTIMORE GAS AND ELECTRIC CHARLES CENTER. P.O. BOX 1475 BALTIMORE, MARYLAND 21203 ARTHUR E. LUNDVALL JR.
"["'*7" 3anuary 18,1983 U.S. Nuclear Regulatory Commission Washington, DC 20555 ATTENTION:
Mr. Darrell G. Eisenhut, Director Division of Licensing
SUBJECT:
Calvert Cliffs Nuclect Power Plant Unit Nos.1 & 2; Docket Nos. 50-317 & 50-318 Potential Steam Generator Related Generic Requirements
REFERENCE:
(a)
Generic Letter 82-32 dated December 9,1982, from D. G. Eisenhut to all PWR Plant Licensees, same subject Gentlemen:
We have reviewed the referenced letter. The time frame alloted for comments has precluded a detailed review of the 200 page enclosure to the letter. However, a cursory review of the enclosure has precipitated some substantive concerns over the validity of some recommendations forwarded in the executive summary of the report.
These comments are provided in the enclosure.
In view of the size and detail of the report, the 30-day comment period seems too short.
We recommend you extend the comment period beyond the 30-day period.
Should you wish to discuss this matter further, please do not hesitate to contact us.
Very truly yours,
._. Q s d Vice Preside t - Supply AEL/LES/gla Enclosure cc:
- 3. A. Biddison, Esquire l
G. F. Trowbridge, Esquire D. H. Jaffe, NRC R. E. Architzel, NRC 8301250102 830118 j
PDR ADOCK 05000317 P
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l ENCLOSURE COMMENTS ON NRC GENERIC LETTER 82-32 i
The report states that "public" risk from steam generator tube rupture was assessed and found to be so low that it has a completely negligible contribution to the value impact comparisons. This means the whole report and recommendations are solely. based on avoidance costs for a forced outage. The NRC seems to be id!ceing a different course of action than previously. Although the avoidance costs for fcrced outages seem to be l
well researched, we feel this type of study should be left to each utility. They would -
have more accurate data for this type of study than the NRC.
j The four Westinghouse plant tube rupture events ca1 sed by loose parts in the steam generators represent all plant operating experience in calculating this event probability.
The incidence of loose parts in Westinghouse supplied generators is admittedly worse. If l
the benefits from improved Quality Assurance for loose parts in steam generators were calculated for each NSSS supplier separately, the results may be different.
A tube rupture is defined in the report (page 111-5-1) as a leak exceeding the capacity of l
the charging pumps. This appears to be an arbitrary classification. The Final Safety Analysis Report for the Calvert Cliffs Nuclear Power Plant uses a double ended tube rupture as the design basis tube failure event. In the words on page 14.15-1, this event results in a leak rate which far exceeds the make-up capacities of the charging pumps. A calculation of leak rates required to empty the pressurizer in the time specified in the Final Safety Analysis Report shows a leak rate in excess of 650 gpm, which exceeded five times the capacity of the available charging pumps (132 gpm).
If this classification is broadened to a larger leak rate, the number of events which are classified as tube ruptures will decline. Page I.1-3 lists the range of leak rates reported -
as 80 gpm to 390 gpm.
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Under Section IV, page 7-1, Section 7.1-1, paragraph 3 states that each licensee shall be required to report all progressive degradation mechanisms presently occurring or likely -
to occur in his plant. The meaning of "likely to occur" is not clearly provided.
l The table on page IV.2-7 shows full length tube inspections are not cost effective from an exposure prevention point of view.
In addition, subset selection / interval change, unscheduled inservice inspection upon shutdown, and reporting do not have a benefit cost in the table. In spite of this, the executive summary lists all these improved Inservice i
Inspection actions as generally very effective. If the executive summary were used alone, it appears that all these actions are very effective and should be implemented. To preclude this misunderstanding, we feel each improved Inservice Inspection action should be separately listed as effective or not effective.
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