ML20024C411

Affidavit of Ej Youngling Re Diesel Generator Cracks. Reasonable Assurance Exists That No Addl Cracks or Leaks in Remaining Cylinder Heads Will Occur Due to 600 H Operation

ML20024C411
Person / Time
Site:	Shoreham File:Long Island Lighting Company icon.png
Issue date:	07/07/1983
From:	Youngling E LONG ISLAND LIGHTING CO.
To:
Shared Package
ML20024C405	List: ML20024C404 ML20024C408 ML20024C411 ML20024C416 ML20024C426
References
ISSUANCES-OL, NUDOCS 8307120601
Download: ML20024C411 (9)

Text

, __

6 ap LILCO, July 7, 1983 UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION Before the Atomic Safety and Licensing Board In the Matter of )

)

LONG ISLAND LIGHTING COMPANY ) Docket No. 50-322 (OL)

)

(Shoreham Nuclear Power Station, )

Unit 1) )

AFFIDAVIT OF EDWARD J. YOUNGLING Edward J. Youngling, being duly sworn, deposes and says as follows:

1. My name is Edward J. Youngling and I am employed by the Long Island Lighting Company (LILCO) as Startup Manager for the Shoreham Nuclear Power Station. My professional quali-fications have been previously submitted to the Board. As Startup Manager, I am responsible for all preoperational test activities.

I also coordinate Checkout and Initial Operation (C&IO) testing and preoperational testing. In this role I have I been directly involved in the testing of Shoreham's diesel gen-i l erators and in resolving related issues that developed during testing.

l Specifically, I am familiar with the County's conten-tion regarding Shoreham's diesel generators.

i i.

t 8307120601 830707  !

PDR ADOCK 05000322 O. PDR

E 2.

i I testified previously in this proceeding as a member of the LILCO panel on the Quality Assurance / Quality Con-trol issues.

I have also submitted two previous affidavits to the Board regarding Shoreham's diesel generators dated May 16, 1983 and June 3, 1983. On June 10, 1983, I appeared before the Board to answer questions regarding Shoreham's diesel genera-tors. ,

3.

This affidavit addresses that portion of SC's con-tention on diesel generators that alleges the diesel generators may not start or operate as required unless and until the cyl-inder head cracking issue is resolved for the Shoreham diesels.

See Memorandum and Order Ruling on Suffolk County's Motion to Admit New Contention (June 22, 1983) at 37. This concern is based on LILCO's detection of a minor water leak in three of the 24 cylinder heads in the diesel generators. To remedy this situation, LILCO replaced the three cylinder heads with improved, current production model cylinder heads. In addi-tion, LILCO intends to replace all the remaining cylinder heads as soon as practicable consistent with the schedule for preoperational testing and fuel load. In the interim, prior to replacement of all cylinder heads, LILCO will implement a sur-veillance ("barring over") procedure to insure that leaks are 2

l l

. . ~ _ _ _ _...-_,..,_r, - . - . . . _ , , , . . .- _ . , _ _ . , . . ..m,- . . . . ....

promptly detected in the unlikely event any occur. Any head exhibiting leakage would be promptly replaced with a new head of the current production model. This affidavit demonstrates (1) that there is a reasonable assur-ance that there will be no further leaks in the remaining cylir. der heads, (2) that LILCO's surveillance procedure

("barring over") provides adequate assurance of reliable rapid start capability by insuring that leaks would be promptly detected and in the unlikely event they do occur, (3) that leakage of the type previously detected at Shoreham, if any were to occur and remain undetected, would not affect the quick start capability or the safe and reli-able operation of the diesel generators, nor would such leakage prevent the diesel genera-tors from carrying their full design electri-cal load.

4.

As noted in my May 16, 1983 affidavit, early in the preoperational testing process, three cylinder heads of the Shoreham diesel generators experienced cracks that resulted from manufacturing casting flaws. In that affidavit, I stated that improved casting techniques and nondestructive testing and inspection procedures have largely eliminated the possibility of casting flaws in current production models thereby greatly reducing the potential for cylinder head cracks. I also stated that LILCO will replace all cylinder heads with those produced

(

l

with improved casting and inspection techniques. Qualified LILCO personnel have conducted an inspection and audit of the improved Delaval process which confirmed that improved casting and inspection techniques have been implemented at Delaval to ensure that casting imperfections of the type previously iden-i tified in the three Shoreham cylinder heads will not occur in the current production model heads. The three cylinder heads that experienced cracks have been replaced with these improved, current production cylinder heads.

5. Failure analyses conducted by the vendor, Transamerica Delaval Inc. (TDI), determined that the cracks were caused by operating stresses from cylinder firing pres-sure.

TDI has informed LILCO that casting flaws exist only in a small percentage of cylinder heads identical to those origi-nally supplied with the Shoreham diesels and that based on ex-perience, cylinder heads that develop leaks similar to those experienced at Shoreham do so prior to completing 600 hours0.00694 days <br />0.167 hours <br />9.920635e-4 weeks <br />2.283e-4 months <br /> of operation.

Each of Shoreham's diesels now has over 600 hours0.00694 days <br />0.167 hours <br />9.920635e-4 weeks <br />2.283e-4 months <br /> of operation (DG 101 - 617 hours0.00714 days <br />0.171 hours <br />0.00102 weeks <br />2.347685e-4 months <br />, DG 102 - 693 hours0.00802 days <br />0.193 hours <br />0.00115 weeks <br />2.636865e-4 months <br />, DG 103 -

809 hours0.00936 days <br />0.225 hours <br />0.00134 weeks <br />3.078245e-4 months <br /> as of June 24, 1983). Because the generators have passed the 600 hour0.00694 days <br />0.167 hours <br />9.920635e-4 weeks <br />2.283e-4 months <br /> threshold, there is a reasonable assurance that there will be no leakage on any of the remaining originally supplied cylinder heads.

i

6. The failure analysis also determined that the cracks were of such a nature that they would not have affected the performance of the diesel generators. The cracks were self-relieving, nonpropagating, and of small sizelf so that they had no impact on the mechanical strength of the head. As noted in my May 16 affidavit, any water that would leak into the combustion chambers as a result of these cracks would be expelled via the exhaust system along with other combustion by-products.

Thus, despite the small leaks that occurred, the reliability of the cylinder heads during operation was not af-fected.

Additionally, there is no impact on the ability of the diesel generator or the individual cylinder head with a crack to carry its full load.

For example, in marine applications, engines with cracked cylinder heads are operated for weeks without any effect on the reliability or operation of the en-gines.

3 1/ In my May 16, 1983 affidavit, of the leaks was at a rate of 9.25 gallons per hour.I reported that the largest This rate wasthe via during exhaust. operation of the diesel and the water was expelled When the combustion chamber was inspected after shutdown, only a small amount of water (approximately a cupful) was found in the combustion chamber.

that the water had in fact been expelled through the exhaustThis confirms (i) during operation and (ii) that the leakage rate after shutdown of the diesel generator.is very low and is no impediment to the rapid start c 5-

- , - . - - --9e,p. p_.-., , , , - - - - . , - ,-~ _- ,,7- w--y,- .-.y- ..

( .

7. Even though LILCO and TDI believe that the number of operating hours on each engine makes it unlikely that any more cylinder heads will experience leaks, LILCO will institute a surveillance procedure ("barring over") by which water leak- ,

age will be promptly detected. This procedure gives further assurance that should a leak occur, it will have no impact on the quick start capability of the diesel generators. This sur-veillance or "barring over" requirement is contained in Shoreham's draft Station Procedure 27.307.02, " Emergency Diesel Generator Cylinder Leak Detection Test." In accordance with this procedure, the plant operator, using the barring device, will mechanically turn the engine over several complete revolu-tions.

Water present in the cylinders will be forced out through the indicator cocks where it will be observed by the inspector.

Water will not be forced out the exhaust system and go undetected because all four valves for each cylinder close prior to the piston reaching top dead center. The inspection intervals specified in SP # 27.307.02 are four, eight and twelve hours after the diesel generator is shut down. This is in accordance with the vendor's recommendation. The "barring over" practice is a well-established one in the large diesel generator industry for exactly the same reasons it is being im-plemented at Shoreham.

8. The surveillance or "barring over" intervals specified in the procedure are appropriate in light of the na-ture of the small leaks and low leakage rates involved in these instances.

TDI's analysis of the three affected Shoreham cyl-2 inder heads indicates that these cylinder heads developed small cracks and leaks as a result of the action of high cylinder firing pressures on the rarely occurring casting flaws in the cylinder heads.

After shutdown, and as the diesel generator cools, the cracks, if any exist, close and leakage stops.

Thus, the first "barring over" is the four hours after shutdown because the temperature in the combustion chamber early in the four hour period following shutdown is sufficiently high that the characteristically small leakage will evaporate. At four hours, however, leakage would begin to be detectable. "Barring over" beyond 12 hcurs after shutdown is unnecessary because by this time the diesel generator has cooled to a steady state standby temperature and cracks, if any existed, would have closed and leakage ceased.

Four hour intervals for surveil-lance and "barring over" are appropriate because post-shutdown leaks of this nature are characteristically of such a slow rate i

that more frequent "barring over" is not necessary.

4 l

i 4

i

, , , , + , , . . . - - - . , . . - ,.-.,,-----.,--n ... . _ . . , , , . , - . - . , , , , . ~ _ , , - - . , - - , - - , , , . , . , , , , , . . , - . - , , ,

l

, .* l 9.

In the unlikely event of any additional leaks at Shoreham, operating personnel, by observing the jacket water level instruments, will be able to detect water leakage during operation.

Leakage occurring after shutdown will be detected by the surveillance ("barring over") procedure. If a leak oc-curs, the inspector is to notify the Watch Engineer who, in turn, will declare the diesel generator inoperable. The cylin-der head must then be replaced. Once an engine is declared in-operable, the technical specifications dictate the course of action to be taken.2/

10.

In summary, given that Shoreham's diesel genera-tors have more than 600 hours0.00694 days <br />0.167 hours <br />9.920635e-4 weeks <br />2.283e-4 months <br /> of operation, there is reasonable assurance, in light of the experience of Delaval with large numbers of identical cylinder heads, that there will not be any additional cracks or leaks in the remaining cylinder heads.

Moreover, LILCO's surveillance ("barring over") procedure pro-vides reasonable assurance of reliable rapid start capability by ensuring that leaks would be promptly detected even in the unlikely event that such additional leaks were to occur. It is y 2/

f During low power testing, only two diesel generators are required 5 3.8.1.2. to be operable under Shoreham Technical Specification der head cracking because if a leak develops,This further lessens a der the low power testing. it will not hin- .

also significant that leaks of the nature detected at Shoreham

-do not affect the safe and reliable operation of the diesel generators, including the quick start capability.

Edward J. Youngling Subscribed and sworn to before me this day of July, 1983.

,. Notary Public i

l l

l l

l l

_ _ _ _ . . - . , - - - _, ,_,. , ,, - --.---c--- ""