ML20086G594
| ML20086G594 | |
| Person / Time | |
|---|---|
| Site: | Quad Cities  |
| Issue date: | 07/07/1995 |
| From: | Schrage J COMMONWEALTH EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9507170004 | |
| Download: ML20086G594 (4) | |
Text
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Commonwealth I'.dison Company I 4(M) Opus 1%ce Downers Grm e, ll. (iO51 %
July 7,1995 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555
Subject:
Quad Cities Nuclear Power Station Unit 2 Third Ten Year Interval Inspection Plan Relief Request CR-15, Revision 0 NRC Docket No. 50-265 This letter transmits Relief Request CR-15, Revision 0, to the subject Inservice Inspection (ISI) Plan. The proposed Relief Request (CR-15) has the potential to impact the current refueling outage for Quad Cities Unit 2.
Proposed Relief Request CR-15 provides alternate provisions from the requirements of the 1989 Edition of ASME XI, IWA-5250(a)(2) for bolted connections. The proposed alternate requirements are consistent with current industry-accepted practices for assessing bolted connections. A copy of the proposed Relief Request is provided as an attachment to this letter.
4 To avoid any notential imoact on the startup from the Unit 2 refuel outace. Comed reauests NRC staff review and approval of Relief Request CR-15 prior to July 13.1995.
If there are any questions or concerns regarding this submittal, please direct them to this office.
Sincerely,
/
. AJ6hn L. Schage
/
Nuclear Licensing Administrator
Attachment:
Relief Request CR-15, Revision 0 cc:
H. J. Miller, Regional Administrator - RIII R. M. Pulsifer, Project Manager - NRR C. G. Miller, Senior Resident Inspector - Quad Cities Office of Nuclear Facility Safety - IDNS k:\\nla\\dreaden\\qua&m wpf (Y
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1 ATTACHMENT Relief Reauest CR-15. Revision 0 1
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Quad Cities Station 3rd Interval Inservice Inspection Plan RELIEF REQUEST NUMBER: CR-15 (Page 1 of 2)
COMPONENT IDENTIFICATION Code Class:
1
References:
IWA-5250(a)(2)
Examination Category:
B-G-2 Item Number:
B7.80
==
Description:==
Bolting Removal When Leakage is Detected at Bolted Connection During System Pressure Test CODE REQUIREMENT IWA-5250(a)(2) requires that if leakage occurs at a bolted connection, associated bolting be removed and visually examined (VT-3) for corrosion.
BASJS FOR RELIEF Reactor Recirculation Pump 2-0202A casing flange leakage has been primarily observed at Quad Cities Station during pump operation for the ASME XI Class 1 system leakage test prior to the pump casing metal reaching normal operating temperature range. This leakage decreases to acceptable levels when the pump casing metal temperature reaches normal operating temperature range and the gaskets are properly seated. The pump manufacturer, Byron-Jackson, has stated that this pump casing flange gasket is not designed to be leak free during " cold" conditions due to minimal " memory" capabilities of the gasket. The origmal gasket was a Flexatallic Type 304 SS and asbestos. The replacement gasket is a Flexicarb spiral wound high purity graphite. Minimal leakage from the pump casing flange is expected at lower temperatures.
During the 1989 refueling outage, minimal leakage was detected at the pump casing flange. The bolts [ phosphate coated, type A193 Gr. B7] were retorqued and during the final containment walkdown, as the pump casing reached normal operating temperature range, the leakage was verified to have stopped. The pump casing flange has been verified during each successive final containment walkdown to not leak. This same phenomenom has been observed upon subsequent plant startups.
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l 10-35 Revision 0 I
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Quad Cities Station 3rd Interval Inservice Inspection Plan RELIEF REQUEST NUMBER CR 15 (Page 2 of 2)
Quad Cities is currently committed to the 1989 Edition of ASME XI. IWA-5250(a)(2) requires that "ifleakage occurs at a bolted connection, the bolting shall be removed, VT-3 visually examined for corrosion, and evaluated in accordance with IWA-3100."
ASME XI Interpretation X1-1-92-48 states that all the bolts in the connection must be removed for examination. The 1989 Addenda to ASME XI allows the removal of i
one bolt, which must be the closest to the source ofleakage.
The subject bolting is extremely difficult to remove and as such, places an unnecessary burden on site personnel resources. Due to the physical configuration of the system, the removal of three casing flange bolts has expended over 48 manhours.
In addition, the physical proximity of the bolted connection places an unnecessary burden on site personnel due to the high dose rates encountered. As a result, the dose rates expended during bolt removal has averaged 238 mrem per bolt. The total dose projected to remove all 16 bolts in the casing flange is 3.8 person rem. Based upon the aforementioned ALARA concerns, Quad Cities desires one time relief specific to the Reactor Recirculation Pump,2-0202A to not remove all 16 pump casing bolts and perform subsequent VT examinations.
PROPOSED ALTERNATE PROVISIONS As an alternate examination, three casing flange bolts closest to the area of the leak were removed and a VT-3 examination was performed in accordance with IWA 5250(a)(2). The three bolts were accepted with no recordable indications. As previously discussed, the 1989 Addenda to ASME XI allows provisions for the removal of one bolt (closest to the leakage source) for examiniation. Although Quad Cities is not currently committed to this addenda of the Code, the proposed alternate provisions are consistent with or more conservative than current industry accepted l
practices for bolted connections. Therefore, additional Reactor Recirculation Pump casing flange bolts will not be removed based upon the results obtained to date. The proposed alternative examinations provide reasonable assurance of the operational readiness of the affected system.
APPLICABLE TIME PERIOD Reliefis requested, on a one time only basis, for the current refueling outage, Q2R13.
10-36 Revision 0