ML19276D621
| ML19276D621 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 12/21/1978 |
| From: | Wigginton D Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| TAC-11055, NUDOCS 7901080107 | |
| Download: ML19276D621 (7) | |
Text
{{#Wiki_filter:f*" '#D, t UNITED STATES [. NUCLEAR REGULATCRY CCMMisstCN f 3 e - di % w4mnarcu c.c.:csss \\ / December 21, 1978 DOCKET NO.: 50-334 LICENSEE: Duquesne Light Company FACILITY: Beaver Valley Power Station, Unit No. 1
SUBJECT:
MEETING
SUMMARY
- CONTAINMENT LINER WELD BOXES (CHANNELS)
The ifcensee and Stone and Webster Engineering Company met with the staff on December 5,1978 to discuss the containment leak testing with the containment liner weld channels unvented at the Beaver Valley Unit No.1. An attendance list is attached as Attachment 1.
Background
The Beater Valley Unit No. I was licensed for full power operation in July 1976. The first integrated leak rate test was perfomed in August of 1975 with the containment liner configuration as described in the Final Safety Analysis Report (FSAR) as amended. The FSAR describes the' containment liner seam welds as having steel channel boxes installed over the welds during the liner construction and assembly. The channel boxes were first installed to test the liner seam welds; the test holes were then plugged with 1/8 inch pipe thread plugs. In October 1977, the Office of Inspection and Enforcement (I&E) requested the Office of Nuclear Reactor Regulation (NRR) to examine the need to vent (unplug) the channel boxes during integrated leak rate testing (ILRT). In December 1977, we infonned I&E that the channel boxes should be vented during the ILRT. Meeting Sumary Although advised by I3E that the test might not be acceptable, the licensee perfomed an ILRT during November 1978 without tenting the channel boxes. This was done to more closely duplicate the first ILRT in 1975. The leakage rate from the November 1978 test was within that allcwed by the Beaver Valley Technical Specifications. The licensee feels that the test should be acceptable and has been supported in this position by Stone arm Webster, the architect engineer respocsible for the Ifner design and construction. b k O( ~
- B.
'ieeting Summary for 2-December 21, 1978 Duquesne Light Company The Stone and Webster position has been that the channels are not load carrying members, were designed, fabricated, and installed to the same level of confidence as the liner seam welds, and were originally tested to static pressures in excess of that required by the ILRT. A comparison of the liner seam welds and channel box was provided by Stone ar.d Webster and is attached as Attachment
- 2. Discussiens, however, brought out differences in channel box / seam weld / plug configurations. On the walls, the channels are internal to containment with vent plugs in the channel box. On the dome, the channels are on the outside of the liner with the plug test holes penetrating the containment liner seam weld. On these deme channels there are also plugs in the channel box.
Stone and Webster has not analyzed the channel boxes for loss of coolant accident (LOCA), seismic, or other conditions. The concero expre; sed by the staff to the licensee was the need to have assurance of the integrity of the liner seam welds in the dome with postulated loosened plugs or partially dislodged (filler weld crack) channel boxes on the interior of the containment as a result of LOCA induced and seismic forces. In as much as the welds covered by these channel boxes were all subjected to a static pressure test prior to plant operation and, since at other plants, venting of similar channel boxes during ILRTs have not uncovered defective liner seam welds, the staff did not object.to Beaver Valley being returned to power while this matter is given further consideration. In addition, Beaver Valley Unit No.1 is not required under Appendix J and their Tech Specs to perform the ILRT upsil 40 + 10 months after preoperational testing. That requirement can still be met at the next refueling now due in March 1979. 4,4emWD 6 m 6e m emuusmDene e e
) Meeting Summary for Duquesne Light Company December 21, 1978 The licensee was told, however, that unless additional information can be developed to otherwise demonstrate the integrity of the channel boxes and pipe thread plugs we would be giving consideration to (1) requiring limited testing of some of the channel box / liner seal weld barriers during the next refueling outage, (2) requiring replacement of all existing threaded (and plugged) holes in the liner seal welds (those with channel boxes outside containment) with qualified filler welds during the next refueling outage, and (3) venting of all reasonably accessible channei be.xes during the next ILRT. The integrity of the repaired liner seal welds could be established by a pressure test before sealing the threaded holes and by applying a pressure / vacuum test on the filler velds. t l /, Dave Wigginton, Project Manager Operating Reactors Braach #1 Division of Operating Reactors
Enclosures:
As Stated cc: w/ enclosures See next page 'h$6Mhe eu em
Meguques e$iht ~ empany Docket File NRC PDR Local PCR ORBI Reading NPR Reading M. Denton E. Case V. Stello D. Eisenhut B. Grimes D. Davis D. Ziemann P. Check G. Lainas A. Schwencer R. Reid T. Ippolito V. Noonan J. McGough Projec* Manager OELD OI&E(3) ACRS (16). C. Parrish NRC Participants TERA J. R. Buchanan Licensee m
fA/Ct CTA AE / CONTAINMENT LEAK TEST WITH CONTAINMENT LINER WELD CHANNELS UNVENTED Meeting December 5,1978 between the Nuclear Regulatory Comission, Duquesne Light Company and Stone and Webster. DLC S&W USNRC s.I- >)f'.i C - M ( I,c g g y Q c Q.. E@ ^ ssCswy-w est, // J. Cv:~u J G MQ '!$/ $ it.ni, w _%.s, b cf $ $ 4 6 4.. D % C h 5
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W Y,r i e,r. (1 -N 72 CCMPARISCN OF LIER FAERICATICN A!C TEST CHA? CIEL FAERICATIONS PREBEOUISITE/ACTICN LINEA PLATE TEST CHAf0fEL 1. MATERIAL SPECIFICATION a) Elev. 690'11" to 720'11" ASTM-A537, GR. 3, ASTM-A131, GR. C (Shell) Quenched and Tempered Charpy test on the above - Min. NDT-50 F !!CNE Chemicals & Physicals YES YES b) Elev. 720'11" to 8 I I, (Shell ASTM-A516, GR. 60, Fine ASTM-A131, GR. C Dome and Bottom Plate) Grained and firmalised Charpy test Min. NDT-20 F NCNE Chemicals & Physicals YES YES 2. '4ELDING a) Method Full Penetration Batt Fillet b) Code I")fi0"'4 G M
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Boiler & Prerwre Vessel Seiler & Pressure Code, Sec. Il Vessel Code, Sec. IX l c) Procedure ilo. (Shell Hirg +) 1-Vertical 205 2C5 2-Horizontal 137 205 3 TEL~ RING & INSPECTIONS a) Visual - 10C% YES YES b) Mag. Particle NO NC c) Dye Penetrant - 1CC% YES YES d) Radiograph - 2% Para e'52.Sec. VIII g Pressure Vessel Code O Me w=+
Pg ? a r ?, ,,.-a -{ PRESEOUISITE/ACTICN LI?E2 PLATE TES"' CHANNFJ, 3 Fr. STING & IiSPECTICI!S (Continued) ~ 4 ) Halogen Leak Test - 50 pai TIS (stw L C_u ~]>d 3 YES G) Air Pressure Test - 50 psi YES IIS %}}