ML20235N222

Comments on Draft SER for Zimmer Nuclear Power Station:Unit 1.List of Various Causes of Containment Related Failures Identified as Potentially Significant Deficiencies Encl

ML20235N222
Person / Time
Site:	Zimmer
Issue date:	11/15/1978
From:	Eaton T Advisory Committee on Reactor Safeguards
To:
References
ACRS-CT-1073A, NUDOCS 8707170478
Download: ML20235N222 (3)

Text

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. PDR 1//y/97

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COMMENTS ON THE DRAFT SAFETY EVALUATION REPORT FOR CG&E's ZIMMER NUCLEAR POWER STATION: UNIT 1; Docket No. 50-358*

by Thomas E. Eaton U.S. NRC/ACRS Consultant Contract No. 11-78-632 15 November 1978

1. The Draft SER indicates (section 3.5.2, p, 3-6) that steam turbine missiles having a low trajectory could not damage the Diesel generators because of a grazing impact with the turbine building floor. Is there a significant potential for damage to the Diesel generators by high trajectory steam turbine missiles?

2. Since the pressure suppression function of the Mark II containment system is an important safety feature of the plant, is it possible that the wetwell spray system should j be assigned a more important role in the Mark II contain- 1 ment system (cf., pp. 6 6-17)? ,

3. On page 6-17, is it possible that the General Electric Co. test program was for the Mark III pressure suppression containment instead of for the Mark II containment?

4. The containment hydrogen recombiner system is located outside containment and is designed for 62 psig (p. 6-33); are the containment intake and discharge openings to this system adeouately protected against jet impact?

5. What is the source of steam for the feedwater pump turbines (p. 7-12) after the reactor is isolated?

6. The suppression pool temperature monitoring system in the l Draft SER (p. 7-19) does not comply with requirements in I the Mark II Generic Acceptance Criteria and Draft Load )

Evaluation Report (cf. pp. III-89 to 111-90).

I DEEIG1:ATtD ORIGINAL G707170478 78111S Certified By PDR ACRS CT-1073A PDR

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COMMENTS ON THE DRAFT SER FOR ZIPMER UNIT 1 (Continued)

7. The Diesel generator fuel oil system contains a " day" tank, cf. p. 9-10, with a capacity of 550 gallons. The EMD 4000 horsepower (nominal) generators have a BSFC (specific fuel consumption) of 0.40 lbm/HP-hr (nominal) and will empty the " day" tank in about 2-1/2 hours.

8. On page 11-9, should the I-131 release be not greater than one Curie per reactor per year?

9. On page 15-3, "the surface heat flux never exceeds 75 per cent" .. of what?

10. On page 15-5 (top), are there no other reactivity insertion transients for the BPR/57

11. On page 15-7, is the primary containment leak rate of 0.635 per cent of the containment volume per day based on the volume being at standard temperature and pressure?

12. In the discussion on the fuel handling accident (section 15.3.3, p. 15-10), is it not also assumed that the fuel fails as the result of the drop?

13. Would the consequences of postulated radioactive releases due to liquid tank failures (section 15.3.6, p. 15-15) be more significant if the postulated liquid flow involved i a surface runoff (instead of ground seepage) which carried the liquid released directly to the Ohio River?

14. Is there any relationship between the motor-generator output voltage regulator failure noted in section 7.2.3,

p. 7-5 and the discussion in section 8.4.1, p. 8-8, which relates to DC power systems?

• During this review of the Zimmer Draft SER, several typing mistakes were identified. This investigator will provide a listing of these corrections if requested by the U.S. NRC.

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i INITIAL FINDINGS:

CAUSES'FOR CONTAINMENT RELATED LITENSEE. EVENT REPORTS (LER's) by Thomas E. Eaton U.S. NRC/RCRS' Consultant

' Contract No. 11-78-632 16 November 1978 Below are listed various causes of containment related failures reported as LER's. These causes are identified in this preliminary listing because their frequency of occurance has identified them as potentially significant deficiencies.

Because this review of LER's has only just started, this list should be considered as preliminary and incomplete.

A. Design of Containment Airlock' Door Interlocks B. Air lock Door Seal Leaks

.C. Airlock Handwheel Seal Leaks 4

D. Weld failures.in the Heat Effected Zone .

E. Liquid Nitrogen Not Ordered (Delivered) Such that Contain-ment can be'Inerted as Required F. Railroad Door Seal Leaks G. Hydraulic Fluid Loss from Seismic Snubbers H. Ice Build-up Interfering with Door Operation in Westinghouse Ice Condenser Containments I. Vibration Fatiguing of Small Pipes and Tubes J. Doors Blocked Open by Workmen to Allow Temporary Hoses, i Wires, etc. to Enter Reduced Pressure Buildings.

K. Oxygen Analyzer Errors l L. Failures in Liquid Nitrogen Supply Systems {

t M. Containment Spray System Component Failures l

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