ML18079A929
| ML18079A929 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 09/10/1979 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Schneider F Public Service Enterprise Group |
| References | |
| NUDOCS 7909190414 | |
| Download: ML18079A929 (5) | |
Text
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UNITED STATES NUCLEAR REGULATORY COMMISSION REGION I 631 PARK AVENUE KING OF PRUSSIA, PENNSYLVANIA 19406 SEP 1 0 1979 Public Service Electric. and Gas Company ATTN:
Mr. F. W. Schneider Vice President - Production 80 Park Place Newark, New Jersey 07101 Gentlemen:
The enclosed Circular No. 79-18 is forwarded to you for information.
No written response is required.
Should you have any questions related to your understanding of the recommendations on this matter, please contact this office.
Sincerely,
~~
~
Boyce H. Grier
~Director
Enclosures:
- 1.
IE Circular No. 79-18
- 2.
List of IE Circulars Issued in Last Six Months cc w/encls:
F. P. Librizzi, General Manager - Electric Production E. N. Schwalje, Manager - Quality Assurance R. L. Mittl, General Manager - Licensing and Environment H. J. Midura, Manager - Salem Generating Station
/c_.f31
. //t>r 79091904-/'--ft l
ENCLOSURE 1
- UNITED STATES Accession No: 7908200385 SSINS No. 6830 NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION ANO ENFORCEMENT WASHINGTON, 0. C. - 20555 PROPER INSTALLATION OF TARGET ROCKSAFETY-RELIEF VALVES Description of Circumstances:
IE Circular No. 79-18 Date:
September 10, 1979 Page 1 of 2 As a result of NRC monitoring of operating experiences involving-the Target Rock safety-relief valve, two potential problems have been identified.
One potential problem is that the performance of the valve has been found to be impaired by either excessive or insufficient insulation around the valve body when installed in its service environment.
The other potential problem is that improper assembly of the modified valve can result in inoperability of the remote air actuator.
The Target Rock safety-relief valve is a dual purpose valve in that overpressure _
response is provided by pilot valve action and automatic depressurization (ADS) is provided by a remote air actuator. Valve operation has been found to be affected by the amount of insulation placed around the valve-body.
A previous IE Bulletin No. 76-06 was issued on July 21, 1976 as a result of operating experiences where excessive insulation was installed on the valve.
The excessive insulation caused excessive heat to be retained producing a higher temperature environment for the elastomeric diaphragm which resulted in accelerated deterioration of the elastomer. Failure of the elastomeric diaphragm, makes the valve.inoperable in the power-operation mode (i.e. manual and ADS).
Subsequently, a silicone-nomex diaphragm was developed by the manufacturer to provide a longer life in high temperature environments..In addition, the IE Bulletin explicitly required that insulation be installed in accordance with the manufacturer's recommendations.
A recent licensee event report from the Monticello facility identified a potential problem resulting from insufficient insulation (i.e. just opposite of the condition addressed by IE Bulletin 7fr-06).
During the performance of special testing of the response to safety-relief valve operation, a valve was discovered to be exceeding its design delay time for opening. _Subsequent inspection and testing of the valve revealed that insufficient insulation may cause condensation to accumulate in the pressure venting ports which then results in delaying the opening of the main disk.
This slower response time IE Circular No. 79-18 Date:
September 10, 1979 Page 2 of 2 is significant with respect to primary system overpressure and"similar transient response analyses.
Although the reported event at Monticello involved the three-stage Target Rock safety-relief valves, the requirements for proper amounts of insulation are similarly applicable to the two-stage Target Rock safety-relief valves.
The second potential problem was recently experienced at the Hatch facility.
The licensee event report indicated that improper assembly of the modified design two-stage valve resulted in preventing the air actuator to function.
During the changeover to modify these valves from the previous three-stage type to the current two-stage design, two valves were inadvertently reassembled with the air-actuator angularly displaced.
This misalignment restricted the air flow via the air inlet port thereby preventing the safety-relief valve from functioning in the air actuation mode.
The misalignment was noted and corrected prior to the return of the reactor to operations.
Recommended Actions for BWR Licensee's Consideration:
All holders of operating licenses for BWR facilities employing Target Rock safety-relief valves should be aware of the potential problems described above.
It is recommended that this matter be reviewed at your facility in the following respects:
- 1.
Verify that the installed Target Rock safety-relief valves include the silicone-nomex diaphragms which have the superior time-temperature-environ-ment characteristics and that these diaphragms are periodically replaced in accordance with the most conservative recommendations of.the reactor vendor or valve manufacturer.
2..
Verify that the thermal insulation on the valve is installed in accordance with the valve manufacturer's recommendation.
- 3.
Verify that procedures,are adequate to assure proper assembly of the air actuator, pilot and main disk in accordance with the vendor*s installa-tion instructions for the two-stage valve.
This Circular is being forwarded for information to all BWR facilities with construction permits and to all other power reactor facilities with an operating license or construction permit.
No written response.to this Circular is required. If you need additional information regarding this matter, contact the Director of the appropriate NRC Regional Office.
Circular No.
79-03 79-04 79-05 79-06 79-07 79-08 79-09 ENCLOSURE 2 LISTING OF IE CIRCULARS ISSUED IN LAST SIX MONTHS Subject First Date of Issue Inadequate Guard 2/23/79 Training/Qualification and Falsified Training Records Loose Lacking Nut on 3/16/79.
Limitorque Valve Operators Moisture Leakage in 3/20/79 Stranded Wire Conductors Failure to Use Syringe 4/19/79 and Bottle Shields in Nuclear Medicine Unexpected Speed 5/2/79 Increase of Reactor Recirculation MG Set Resulted in Reactor Power Increase Attempted Extortion-5/18/79 Low Enriched Uranium Occurrences of Split 6/22/79 or Punctured Regulator Diaphragms in Certain Self-Contained Breathing Apparatus
~~----*-_:.;_ __________ --__ --
IE Circular No. 79-18 Date:
September 10, 1979 Page 1 of 2 Issued To All Holders of and Applicants for Special Nuclear Material Licenses in Safeguards Group I All Power Reactor Facilities with an OL or CP All Power Reactor Facilities with an OL or CP All Holders of Medical Licenses Except Teletherapy Licenses All BWR Power Reactor Facilities with an OL or CP All Fuel Facilities and Licensed Reactors A 1.1 Materials Priority I, Fuel Cycle and Operating Reactor Licensees Circular No.
79-10 79-11 79-12 79-13 79-14 79-15 79-16 79-17 2
. LISTING OF IE CIRCULARS ISSUED IN LAST SIX MONTHS Subject First Date of Issue Pipefittings Manu-6/26/79 f actured from Unacceptable Material Design/Construction 6/27/79 Interface Problem Potential Diesel 6/28/79 Generator Turbo-charger Problem Replacement of Diesel 7/16/79 Fire Pump Starting Contactors Unauthorized Procure-7/16/79 ment and Distribution of Xenon-133 Bursting of High Pres-8/8/79 sure Hose and Malfunc-tion of Relief Valve 11011 Ring in Certairi Self-Contained Breathing Apparatus Excessive Radiation 8/16/79 Exposures to Members Of The General Public And A Radiographer Contact Problem in 8/14/79 SB-12 Switches on General Electric Metalclad Circuit Breakers IE Circular No. 79-18 Date:
September 10~ 1979 Page 2 of 2 Issued to*
All Power Reactor Facilities with an OL or CP All Applicants for, and Holders of CPs All Power Reactor Facilities with an OL or CP All Power Reactor Facilities with an OL or CP