ML19224A357
| ML19224A357 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 12/19/1978 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Herbein J METROPOLITAN EDISON CO. |
| References | |
| NUDOCS 7901030028 | |
| Download: ML19224A357 (1) | |
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' "Ic UNITED STATES og
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g KING OF PRUSSI A, FeNNSYLV ANI A 19406 December 19, 1978 Docket Nos. 50-289 50-320 Metropolitan Edison Company ATTN:
Mr. J. G. Herbein Vice President - Generation P. O. Box 542 Reading, Pennsylvania 19640 Gentlemen:
The enclosed Bulletin 78-14 is fortfarded to you for information.
No written response is required.
If you desire additional information regarding this matter, please contact this office.
Sincerely, LYf4 Boyce H. Grier Director
Enclosures:
1.
List of IE Bulletins Issued in 1978 cc w/encls:
E. G. Wallace, Licensing Manager J. J. Barton, Project Manager R. C. Arnold, Vice President - Generation L. L. Lawyer, Manager - Generation Operations - Nuclear G
P. Miller, Superintendent J. L. Seelinger, Unit 1 Superintendent J. B. Logan, Unit 2 Superintendent G. A. Kunder, Unit 2 Superintendent - Technical Support I. R. Finfrock, Jr.
Mr. R. Conrad G. F. Trowbridge, Esquire Miss Mary V. Southard, Chairman, Citizens for a Safe Environment 4 r,3
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UNITED STATES NUCLEAR REGULATORY C0FNISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 IE Bulletin No. 78-14 Date:
December 19, 1978 Page 1 of 3 DETERIORATION OF BUNA-N COMP 0NENTS IN ASCO SOLEN 0 IDS Description of Circumstances:
Following a reactor scram at the Monticello Nuclear Power Station on July 27, 1978, one control rod was determined to have a slow scram insertion time.
While measuring the average control rod scram insertion times (as required by Technical Specifications), the same control rod failed to scram.
Subsequent investigation revealed that a Buna-N disc in the scram pilot valve solenoid core assembly had fractured.
Small pieces of the Buna-N material wedged between the core assembly and the valve pilot body.
This prevented proper movement of the core assembly (plunger), and thus prevented the valve from properly venting control air from the sc.am valves.
A similar event occurred during scram testing on June 5,1978.
On both occasions the contcol rod failed to scram during control rod surveillance testing.
In these instances, had a scram occurred during normal operation of the reactor, the affected rods would have inserted by action of the backup scram solenoid valves.
The reactor was placed in cold shutdown on July 28, 1978.
All of the scram pilot solenoid valves and scram backup valves were disassembled and inspected.
Six additional fractured Buna-N discs were found, all in scram pilot solenoid valves.
Northern States Power Company replaced the plunger Buna-N discs in all 242 scram pilot valves and the 2 backup scram valves.
In addition to the Monticello failures, similar events were recently reported from the Big Rock Point and Pilgrim facilities.
At Big Rock Point, two failures were experienced in October while at Pilgrim one failure was found in July and two in December.
All of these failures were encountered during surveillance testing.
General Electric had previously issued Service Information Letters, SIL 128 (March 31,1975) and SIL 128 Revision I (January 30, 1976),
addressing the deterioration through natural aging of Buna-N components in CRD scram pilot valves.
These letters recommended that a maintenance program be adopted which replaced certain Buna-N components in scram pilot valves on a regularly scheduled basis.
However, the Buna-N discs eF0~:
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IE Bulletin No. 78-14 Date:
December 19, 1978 Page 2 of 3 in the scram pilot valve core assemblies were not included in these recommendations.
As a result of the Monticello experience and subsequent investigation, General Electric has issued in August 1978, SIL 128 Revision 1, Supplement 1, which recommends that all BWR operators take the following actions:
" Establish a preventive maintenance program to replace all core assemblies, diaphragms and associated parts in all CRD scram pilot valves, backup scram valves, scram discharge volume vent and drain pilot valves, and scram discharge volume test valves, at periodic intervals.
The Buna-N parts used in these valves have at least a seven year shelf and in-service life from the packaging date on the rebuild kit. Thus, the valves should be rebuilt periodically to assure that the Buna-N parts are not used in excess of seven years.
It is recommended that the work be scheduled in any one outage such that the associated CRDs are selected from a distributed checkerboard pattern.
The remaining valves can be rebuilt during subsequent outages."
For clarity, it is noted that the above seven year limit recommended by GE includes all of the time from packaging through installation to the end of service life.
In addition, it is noted that the March 31, 1975 issue of SIL 128 stated that the design specification for Buna-N specified a minimum design life of three years.
Action to be Taken by Licensees:
For all GE BWR power reactor facilities with an operating licence:
1.
Review Buna-N material applications in your control rod scrcm systems and determine the time since installation, and for installed material, the time since packaging.
2.
Report the results of the review set forth in item 1 above and describe your schedule for replacement, both in response to this Bulletin and for periodic maintenance.
3.
Describe the bases for your schedule of replacement identified in response to item 2 above.
Justify any proposed replacement time in excess of three years.
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IE Bulletin No. 78-14 Date:
December 19, 1978 Page 3 of 3 4.
Within 45 calendar days of the date of issue of this Bulletin, report in writing to the Director of the appropriate NRC Regional Office, the results of your review, schedule and bases for replacement with regard to Items 1 through 3.
A copy of your report should be sent to the United States Nuclear Regulatory Commission, Office of Inspection and Enforcement, Division of Reactor Operations Inspection, Washington, D.C.
20555.
For all BWR facilities with a construction permit and all other power reactor facilities with an operating license or cJnstruction permit, this Bulletin is for information only and no written response is requi red.
Approved by GA0 B180225 (R0072); clearance expires 7/31/80. Ar sval was given under a blanket clearance specifically for identified generic problems.
Enclosure:
IE Bulletins Issued in 1978 r
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IE Bulletin No. 78-14 Date:
December 19, 1978 Page 1 of 2 LISTING OF IE BULLETINS ISSUED IN 1978 Bulletin Subject Date Issued Issued To No.
78-01 Flammable ^ontact -
1/16/78 All Power Reactor Arm Retainers in G.E.
Facilities with an CR120A Relays Operating License (0L) or Construction Permit (CP) 78-02 Terminal Block 1/30/78 All Power Reactor Qualification Facilities with an OL or CP 78-03 Potential Explosive 2/8/78 All BWR Power Gas Mixture Accumula-Peactor Facilities tions Associated with with an OL or CP BWR Offgas System Operations 78-04 Environmental Quali-2/21/78 All Power Reactoc fication of Certain Facilities with an Stem Mounted Limit OL or CP Switches Inside Reactor Containment 78-05 Malfunctioning of 4/14/78 All Power Reactor Circuit Breaker Facilities with an Auxiliary Contact OL or CP Mechanism-General Model CR105X 78-06 Defective Cutler-5/31/78 All Power Reactor Hammer, Type M Relays Facilities with an With DC Coils OL or CP 78-07 Protection afforded 6/12/78 All Power Reactor by Air-Line Respirators Facilities with an and Supplied-Air Hoods OL, all Class E and F Research Reactors with an OL, all Fuel Cycle Facilities with an OL, and all Priority 1 Material Licensees 4-iC2
IE Bulletin No. 78-14 Date:
December 19, 1978 Page 2 of 2 LISTING OF IE BULLETINS ISSUED IN 1978 Bulletin Subject Date Issued Issued To No.
78-08 Radiation Levels frca 6/12/78 All Power, Test, and Fuel Element Transfer Research Reactor Tubes Facilities with an OL having Fuel Element Transfer Tubes.
78-09 BWR Drywell Leakage 6/14/78 All BWR Power Paths Associated with Reactor Facilities Inadequate Drywell with an OL (for action)
Closures or CP (for information).
78-10 Bergen-Paterson 6/27/78 All Power Reactor Hydraulic Shock Facilities with an Suppressor Accumulator OL or CP Spring Coils 78-11 Examination of Mark I 7/ 21/78 BWR Power Reactor Containment Torus Facilities with an OL Welds for action:
Peach Bottom 2 and 3, Quad Cities 1 and 2, Hatch 1, Monticello and Vermont Yankee.
All other BWR Power Reactor Facilities with an OL for information.
78-12 Atypical Weld Material 9/29/78 All Power Reactor in Reactor Pressure Facilities with an Vessel Welds OL or CP,78-12A Atypical Weld Material 11/24/78 All Power Reactor in Reactor Pressure Facilities with an Vessel Welds OL or CP 78-13 Failures in Source Heads 10/27/78 All General and of Kay-Ray, Inc., Gauges Specific Licensees Models 7050, 7050B, 7051 with the subject 7051B, 7060, 7060B, 7061 Kay-Ray Gauges and 7061B
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