ML19290C932
| ML19290C932 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 12/28/1979 |
| From: | Counsil W NORTHEAST UTILITIES |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| IEB-79-14, NUDOCS 8002150097 | |
| Download: ML19290C932 (4) | |
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L a :C:::0:: f=0~.?l December 28, 1979 Docket No. 50-245 Mr. Boyce H. Grier, Director Region 1 Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406
References:
(1)
W. G. Counsil letter to B. H. Grier dated November 8,1979.
(2)
W. G. Counsil letter to B. H. Grier dated September 28, 1979.
(3)
W. G. Counsil letter to B. H. Grier dated August 31, 1979.
(4)
W. G. Counsil letter to B. H. Grier dated August 1,1979.
Gentlemen:
Millstone Nuclear Power Station, Unit No.1 Seismic Analysis for As-Built Safety-Related Piping Systems References (1) through (4) provided status reports of the program required to respond to I&E Bulletin No. 79-14.
This letter transmits an update report and schedule for reanalysis per our commitment in Reference (1).
If additional information is needed or quescions arise, please contact us.
Very truly yours, NORTHEAST NUCLEAR E1 ERG' COMPANY W. G. Counsil Vice President Enclosure 1
8002150 h
PROGRESS REPORT MILLSTONE NUCLEAR POWER STATION, UNIT NO.1 I&E BULLETIN NO. 79-14 DECEMBER 28, 1979 As outlined in previous submittals, the inspection program of seismic Categury I systems is continuing per the requirements of I&E Bulletin No. 79-14.
During a recent short maintenance outage, a portion of the normally inaccessible systems were verified as outlined below:
Linear Feet Hanger / Restraints of Pine Verified Condensate System 320 19 Feedwater Systen 650 44 Fire, Domestic, Condensate and Transfer System
- 290 2fl Total 1,260 73
- Inaccessible portion completed.
The above inspections bring the total inaccessible area piping verified to date to 1,400 feet.
The attached Table 1 presents the most recent status of the inspection and measurement phases of the program.
100% of all accessible areas and 18% of the inaccessible seismic Category I piping have been examined.
This represents 68% of all piping which was to be scrutinized.
Since extensive preparations have been accomplished for the remaining inspections, the percentages given for the remaining work are not expected to change.
The following systems are presently scheduled for partial reanalysis.
It is anticipated that all piping reanalysis will be completed oa or before September 31, 1980.
The hanger / restraint reviews will be completed shortly af ter the completion of piping reanalysis.
This is necessary since the loadings from the reanalysis are necessary to verify the structural integrity of the hangers /res traints.
o Diesel Generator Fuel Oil o Standby Gas Treatment o Condensate o Fuel Pool Cooling o
.autdown Cooling o Reactor Building Component Cooling Water o Atmospheric Control
- o Standby Liquid Control o Feedwater o Secondary Cooling o Control Rod Drive o Isolation Condenser o Core Spray o Containment Cooling Service Water o Service Water o LPCI It should be noted that only several of the systems listed will require complete reanalysis. The most common ressons for reanalysis are the addition of branch connections that were not considered in the original design calculations and the mislocation of hangers or restraints. These areas appear to match the drawings but will be reanalyzed to ensure seismic adequacy.
Engineering reviews and stress analysis reviews accomplished by our architect engineering firm have not uncovered any nonconformances, which have not either been corrected by field modifications in accordance with technical specifications as described in References (1) through (4) of the transmittal letter, or deemed acceptable by engineering review / analysis.
In all cases, the seismic integrity and safe shutdown capabilities of the plant have not been jeopardized.
Based upon the high degree of confidence derived from the inspections that have been completed and the system work and ISI inside the drywell as outlined in References (1), (2), (3), and (4) and within this report, the most prudent course available is the examination of the remaining inaccessible areas at the next refueling outage.
Preparations have been completed to organize to the maximum extent possible to complete the surveys of inaccessible piping in the most expeditious and accurate manner possible.
...'s' TABLE 1 MILLSTONE UNIT NO. 1 IE 79-14 AS BUILT NERIFICATION PROJECT INSPECTION & MEASURDGhT SLHMARY ITEM QUANTITY.
PERCENT Total Number of Systems to be Investigated 20 18
- Accessible
- Inaccessible 16 Total Linear Feet to be Investigated (Accessible & Inaccessible) 22,192 FT 100%
- Accessible Piping 13,718 FT.
62%
- Inaccessible Piping 8,~474 FT 38%
Total Linear Feet Verified to Date 15,118.FT 68%
- Accessible Piping 13,718 FT 1007.
- Inaceessible Piping 1,400 FT 18%
Total Number of Supports & Restraint to be Investigated (Accessible & Inaccessible) 1,620 100%
- Accessible Supports & Restraints 994-61%
- Inaccessible Supports & Restraints 626 39%
Total Supports & Rectraints Verified to Date 1,081 67%
- Accessible Supports & Restraints 994 100%
87 16%
- Inaccessible Supports & Restraints
.