ML20206C093
| ML20206C093 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 11/09/1988 |
| From: | Scace S NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| MP-12444, NUDOCS 8811160094 | |
| Download: ML20206C093 (3) | |
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(203) 665-5000 November 9, 1988 MP-12444 Docket No.:
50-423 Re:
10CTR50.36 U. S. Nuclear Regulatory Cc:=ission Attn: Document Control Desk Washington, D. C. 20555
References:
(1)
Special Report, S. E. Scace Letter to U. S. Nuclear Regulatory Commissi0n, Millstone Nuclear Power Station, Unit No. 3, Area Tamperature Monitoring - Centainment (CS-01), dated July 19, 1988 (2)
E. J. Mroc:ka Letter to U. S. Nuclear Regulatory CC."=issien, Millstone Nuclear Power Station, Unit No. 3, Pr0 posed Revision to Technical Specifications Area Temperature Monitoring - Containment, dated June 21, 1988 (3)
D. H. Jaffe Letter to E. J. Mroc:ka, Issuance of Amandment (TAC No. 67072), dated Octcber 3, 1986:
Amencment No. 25 to facility Operating License No. NPF-49 for Millstone Nuclear Pcwer Station, Unit No. 3 Gentlemen:
MILLSTONE NUCLEAR PCWER STATION, UNIT No. 3 AREA TEMPEPATURE MONITORING - Pressuri:er Cubicle (CS-03)
The Special Report noted in Reference No. (1), indicated that on June 21, 1988, Northeast Nuclear Energy Ccmpany submitted a prep 0 sed license amendment to facility cperating license NPT-49, to incorporate changes to Millstone Unit No. 3 Technical Specification Table 3.7-6 (Referer.ce L. (2)).
Specifically, t.he prcpesed changes to Table 3.7-6 were submitted to create two new envirorcental :enes, cne of which is CS-03, F assuri:er Cuticle and to raise the Maximum Ncrmal Excursion (i.e. the Technical Specification) temperature limit f rem 120 degrees to 130 degrees.
One of the reasons for the proposed license amendment was that 3ECS-TElD moniters a specific well defined area, i.e. the Pressuri:er Cubicle, which has indicated a higher normal ma::imum average temperature value than originally piedicted for Containment Area C5-01.
The revised tuermal life calculations, tased on the Maximum Normal Excursien value of 130 degrees Tahrenheit, have indicated continued operability of the envircnmentally qualified eqvipment located inside the Pressuri:er Cubicle withcut significant i:rpact en the thermal lite characteristics or the equipment.
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The Special Report in Reference No. (1) also indicated that temperature excursions inside the Pressurizer Cubicle would not be reported individually as they occur, unless the area temperature exceeded 130 degrees Tahrenheit.
Instead, within thirty days after receipt of the License Amendment, a Special Report would be submitted, if required, documenting all temperature excursions inside the Fressurizer Cubicle, during the period from submittal of tha Special Report (Reference No. (1))
to receipt of the License Amendment (Reference No. (3)). Accordingly, this Special Report is being submitted.
Subsequent to submittal of the Special Report in Reference No. (1), there have been five (5) instances in which area temperature inside the Pressurizer Cubicle, as indicated by 3ECS-TE137, has exceeded the original Technical Specification temperature limit of 120 degrees, for a duration exceeding eight hcurs. The dates en which the temperature excursiens began are July 12, 14, 18, August 27 and October 10. These temperature excursions are attributed to normal operating temperature influences and the inherent design of the Presmeriter Cubicle.
On July 12, 1988, at 1245 hours0.0144 days <br />0.346 hours <br />0.00206 weeks <br />4.737225e-4 months <br />, with the plant in Mode 1 at 100% power, temperature element 3ECS-TE137 indicated that the area temperature inside the Pressurizer Cubicle was greater than 120 degrees for a duration greater than 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.
The duration of the temperature excursion was approximately 22 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br />, with a maximum temperature of 120.3 degrees during the temperature excursion.
July 14, at 0223, another temperature excursion occurred. The approximate duration of the temperature excursion was 46 hours5.324074e-4 days <br />0.0128 hours <br />7.60582e-5 weeks <br />1.7503e-5 months <br />, with a maximum temperature of 120.3 degrees. The temperature excursion on July 18 began at 1711. The approximate duration of the te.tperature excursion was 18 days, with a maximum temperature of 124.3 degrees.
The temperature excursion on August 27, began at 0208.
The approximate duration of the temperature excursion was 40 days with a maximum temperature of 122.3 degrees. The temperature excursion on October 10 began at 0059. The approximate duration of the temperature excursion was 25 hcurs with a maximum temperature of 120.4 degrees.
The following is a list of affected equipment for 3ECS-TE137 (Pressurizer cubicle):
3RCS*MV8000A - Pressurizer Relief Isolatien valve 3RCS*MV8000B - Pressuriser Relief Isolatien Valve 3RCS*PCV455A - Pressurizer Power Operated Relief Valve 3RCS*PCV456 - Pressurizer Power Operated Relief Valve 3RCS*SV8095A - Reactor vessel Head Vent Isolation Valve 3RCS*SV8095B - Reactor vessel Head Vent Isolation Valve 3RCS*SV8096A - Reactor Vessel Head Vent Isolation valve 3RCS*SV8096B - Reactor Vessel Head Vent Isolation Valve
e There have been no temperature excursier,s inside the Pressurizer Cubicle, in excess of the new Technical Specification temperature limit of 130 degrees, during the time period between submittal of
.e Special Report documented in Reference No. (1) and receipt of License Amendment No. 25 (Reference No. (3)).
The licensee contact for this Special Report is Vere Joseph, who may be contacted at (203) 447-1791, ext. 5571.
Very truly yours, NORTHEAST NUCLEAR ENERGY CCMPANY cf&
CM' Stephen E. Scace Station Superintendent Hillstone Nuclear Power Station SES/VRJ:lfg ec: W. T. Russell, Region I Administrator D. H. Jaffe, NRC Project Manager, Millstone Units No. 2 and 3 W. J. Raymond, Senior Resident Inspector, Millstone Units No.1, 2, and 3 1
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