ML20247E741
| ML20247E741 | |
| Person / Time | |
|---|---|
| Site: | Byron  |
| Issue date: | 07/20/1989 |
| From: | Chrzanowski R COMMONWEALTH EDISON CO. |
| To: | Murley T Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8907260298 | |
| Download: ML20247E741 (4) | |
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Cimm5nwnith Edis:n 2.
72 West Adams Street, Chicago, Illinois t\\U Address Reply to: Post OTfice Box 767~..
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= Chl:ago, lihnois 00690 0767 July 20, 1989 Gl Dr. Thomas E. Murley, Director-Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555 l
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Subject:
. Byron Station Units.I and 2 Ultimate Heat Sink Technical Specification Amendment liRC DockeJ; jing. 50-454 and 50-455
Reference:
(a): May 23, 1989, letter from R. A. Chrzanowski to T..E. Murley Dear Dr. Murleys i
In reference (a) Commonwealth Edison submitted a proposed Technical'
- l Specification amendment regarding the Byron Station ultimate heat sink.. On July l
11, 1989, a teleconference was held between Commonwealth Edison and members of-your staff to discuss the specific proposed changes. The proposed Action-Statement C requirements were discussed in detail. The teleconference ended with the proposed changes to Action Statement C replaced with the original action
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requirements. However, at that time Commonwealth Edison requested permission'to i
submit further justification to support a compromise requirement for Actio.n l
Statement'C. This letter provides the revised Action State. ment C and justification for the change.
i Commonwealth Edison requests the. incorporation of this change into the i
proposed amendment.
j Attachment A to this letter contains the justification for the revision.
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Attachment B contains the revised Technical Specification page. Attachment C provides a listing of the types of maintenance activities and the estimated time
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.to complete each activity.
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The scope E t.his submitt.ed is encompassed oy tne original r equest.
therefore, the significant hazards' evaluation submitted in reference (a) remains I
valid.
Please direct any further question on this matter to this office.
Very truly yours, i
R. A.
Irzanowski Nuclear L' ensing Administrator l
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[ 001 Region III Office LJ N. Olshan - NRR I
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l Office of Nuclear Facility Safety - IDNS G907260298 890720 7
PDR ADOCK 05000454 P
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h*IZAGlMENZ_.A
@SIl F I C ATIDNEl_ EXTENRING_THE._ISSEHTIAL_SERY1C E WATEILMhKE-UE._EUMP OUT-OF~_SIRVICE TIME The two essential service water rnakeup pumps provid9 the design makeup source to the UHS for both units and are required to be operable in modes 1, 2, 3, & 4.
Since plant outages are planned for one unit during which time the other unit is in operation, it is not possible to do any maintenance that takes longer than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> without shutting down both units. This is an undue hardship as adequate preventative maintenance on the essential service makeup pumps would thus cause a two unit shutdown. The undesirable alternative would be to never do any extended maintenance activities on the j
essential service water makeup pumps. This is not acceptable as it would be l
prudent to do required maintenance on these pumps as they perform the safety l
function of providing makeup to the UHS.
At the present, major maintenance l
activit y has not been required. The estimated time to overhaul the essential l
service water makeup pump engine is 14 days (see Table 1 in Attachment C).
l This maintenance would be done if pump performance warranted it as recommended i
by the vendor and would be a planned maintenance activity.
In addition, there are other urgianned maintenance activities that may be required on the essential service makeup pumps and/or systems which could 'ake longer than the 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, and thus could result in a two unit shutdown.
The revised change to Action Statement C ensures that only one essential service water makeup pump is inoperable at any time.
As with the present Technical Specification, 3/4.7.5, if two essential service water makeup pwnps are inoperable, action per 3.0.3 would be taken to place both units in Hot Standby within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. Hot Shutdown within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, and Cold Shutdown within the subsequent 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The revised Action Statement C. allows one essential service water makeup pump to
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be inoperable for 7 days af ter the same train deep well pump is verified l
operable within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> with basin level 182% and every two hour level is verified 182%.
If the inoperable essential service water makeup was not restored to operable status within 7 dayc, per the revised Action Statement C.,
action would he taken to be in Hot Standby within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and
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Cold Shutdown within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. Additionally, for infrequent makeup pump inspection and extended maintenance when at least one unit is in Mode 5 or 6, the 7 day time limit may be extended to 14 days.
The deep well pumps have been demonstrated seismically qualified and capable of providing a safe reliable backup makeup supply to the UHS,,heeting the single failure criteria under the worst accident condition - a BOCA on one unit operating at design load and the other unit shutting down.
Thus with the above justification, Commonwealth Edison believes that the revision to Action Statement C is war ranted aad would allow preventative maintenance and any required maintenance to be performed and thus ensure a l
continued safe reliable UHS makeup source without requiring both units to be shutdown.
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b ATTACHMENT B l
EGY16ED 1BEERT 1 C.
With one essential service water makeup pump inoperable within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> either:
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Restore the inoperable essential service water makeup pump to 1
Verify that the same train deep well pump is OPERABLE with its UHS cooling tower basin level 18?%.
Continue to verify basin level is 182% every two hours and restore the inoperable essential service water makeup pump to OPERABLE STATUS within
- 7 days.
(*This can be extended to 14 days for Essential Service Water Makeup pump inspection and extended maintenance during the time when at least 1 unit is in Mode 5 or 6.)
Otherwise be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD-SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
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AIIACHMENT__C 4
IABLE_1 Maintenance _.Activl.ty E.Etimated_.T.ima 1.
Engine overhau1* including cat-of-service, 14 days work, testing end return-t:>-service. Time includes replacement of any parts found deficient during the overhaul.
- This maintenance would be done as
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recommended by the vendor at a given l
runtime.
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2.
Other required maintenance activities due to various causes. Time includes l-out-of-service, testing, and return-to-service.
a.
Gearbox repair due to high vibration 7-9 days b.
Partial teerdown of engine 7 days 1
c.
G vernor replacement 7 days d.
Flywheel replacement 7 days l
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