ML20207L229
| ML20207L229 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 12/30/1986 |
| From: | Russell Gibbs TENNESSEE VALLEY AUTHORITY |
| To: | |
| Shared Package | |
| ML20207K584 | List: |
| References | |
| 232.3-(B), 232.3-(B)-R01, 232.3-(B)-R1, NUDOCS 8701120036 | |
| Download: ML20207L229 (12) | |
Text
9 TVA EMPLOYEE CONCERNS REPORT NUM8tH: 232.3 (B)
SPECIAL PROGRAM REPORT TYPE: SEQUOYAH ELEMENT REVISION NUMBER: 1 TITLE: PIPING AND VALVE DESIGN Improper Piping Insulation Material PAGE 1 0F 11 REASON FOR REVISION:
Rev. 1: Addition of concern No. I-85-106-SQN to scope of element and incorporation of Senior Review Panel Rev. O coments.
PREPARATION U PREPARED BY:
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APPROVED BY:
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TVA EMPLOYEE CONCERNS REPORT NUMBER: 232.3 (B)
SPECIAL PROGRAM REVISION NUMBER: 1
(, ~
( PAGE 2 0F 11
- 1. CHARACTERIZATION OF ISSUE (S):
Concerns: Issues:
EX-85-089-002 a. The physical durability of the soft "CI feels that improper insulation (rock wool) type piping insulation materials were installed in many material widely used at WBNP and at aspects of WBNP construction. SQNP may not provide as satisfactory CI expressed that most of the a service life as would a " harder" insulation installed was 'SOF' material .
insulation (' Rock Wool'),
covered by a metal sheath. CI b. The types of nonmetallic thermal stated that this type of insul- insulation being installed at SQN ation is easily damaged, and is plant on austelitic stainless steel subject to deterioration due to components in safety-related systems vibration over long periods of may be of unacceptable quality.
time. CI expressed that a
' Harder' type of insulation should have been used."
/
I I-85-106-SQN "The employee was concerned about the quality of nonmetallic thermal insulation being installed on austenitic stainless steel safety-related systems. He stated that in past experience at other nuclear plants the types of insula-tion that TVA is using at Sequoyah would not be acceptable. He stated that he had questioned the use of these types of insulation about two years prior to the plant staff and had been told that everything was okay. He was looking for an independent assessment."
- 2. HAVE ISSUES BEEN IDENTIFIED IN ANOTHER SYSTEMATIC ANALYSIS? YES X NO Ide.-+1fied by: Nuclear Safety Review Staff (NSRS)
Date: 12/27/85 0082D 12/04/86
-~ . .- ._- - - . - _ _
TVA EMPLOYEE CONCERNS REPORT NUMBER: 232.3(B)
SPECIAL PROGRAM REVISION NUMBER: 1 6?_.
\" PAGE 3 0F 11 Documentation Identifiers:
NSRS Investigation Report No. I-85-106-SON
- 3. DOCUMENT NOS., TAG NOS., LOCATIONS OR OTHER SPECIFIC DESCRIPTIVE IDENTIFICATIONS STATED IN ELEMENT:
Piping insulation, " rock wool," and nonmetallic insulation
- 4. INTERVIEW FILES REVIEWED:
EX-85-089-002 I-85-106-SQN Files reviewed October 8, 1986, contained only K-forms.
- 5. DOCUMENTS REVIEWED RELATED TO THE ELEMENT:
See Appendix A.
- 6. WHAT REGULATIONS, LICENSING COMMITMENTS, DESIGN REQUIREMENTS OR OTHER APPLY OR CONTROL IN THIS AREA?
See Appendix A.
- 7. LIST REQUESTS FOR INFORMATION, MEETINGS, TELEPHONE CALLS, AND OTHER DISCUSSIONS RELATED TO ELEMENT.
See Appendix A.
- 8. EVALUATION PROCESS:
- a. Reviewed TVA Mechanical Design Guide DG-M18.9.1 " Insulation for Piping and Gauipment in Nuclear Power Plants."
- b. Reviewed TVA Sequoyah Design Criteria for insulation requirements inside and outside containment,
- c. Reviewed TVA specifications for Sequoyah insulation supply
. and installation inside and outside containment.
00820 12/04/86
TVA EMPLOYEE CONCERNS REPORT NUMBER: 232.3 (B)
SPECIAL PROGRAM REVISION NUMBER: 1 6, _
\ PAGE 4 0F 11
- d. Reviewed manufacturer's product data sheets for the mineral fiber insulation materials installed at SON and WBN Plants.
- e. Reviewed related ASTM Standards for mineral fiber insulation materials.
- f. Reviewed TVA Nuclear Safety Review Staff (NSRS) Investigation Report No. I-85-106-SQN.
- g. Reviewed TVA SQN Plant Standard Practices and Procedures for i controlling the procurement, storage and installation of '
replacement nonmetallic thermal insulation on austenitic stainless steel.
- 9. DISCUSSION, FINDINGS, AND CONCLUSIONS:
Discussion:
Issue "a"
(
The first concern questions the durability of the sof t (rock wool) piping insulation installed at WBNP because of its alleged susceptibility to damage from abuse and long-term deterioration when exposed to vibration. Based on discussion with the insulation contractor, the term "SOF" (as quoted on the K-form) does not identify any type or brand name of insulation used at WBN.
Therefore, it is interpreted to mean " Soft."
- Rock wool is one of several mineral substances used in the j manufacture of the fibrous type of mass insulation. " Mineral l Fiber" is the ASTM Standard generic term for insulation material l composed principally of fibers manufactured from molten mineral substances such as rock, slag, or glass, with or without binders.
The TVA Insulation Design Guide ( App. A, 5.a) provides general and specific requirements, standards, and application guidelines for various types of insulation to be used in nuclear power plants including all metal reflective types for piping and equipment inside containment and mass types for other piping, equipment and ducts. The TVA insulation specifications ( App. A, 5.d and 5.e) l provide specific requirements for the procurement and installation l
of piping insulation at WBN and SON Plants.
i 00820 12/04/86
TVA EMPLOYEE CONCERNS REPORT NUMBER: 232.3(B)
SPECIAL PROGRAM 7, _ REVISION NUM8ER: 1 t
PAGE 5 0F 11 At SQN plant the majority of installed insulation is molded calcium silicate. However, at SQN (and WBN) mineral fiber insulation has been applied to some piping outside of containment only (excluding the mineral fiber block used in the main piping containment penetrations). Typically mineral fiber insulation is installed on heat traced piping containing borated water, Essential Raw Cooling Water (ERCW) sptem piping, Raw Cooling Water (RCW) system piping, and some exposed drainage piping. Two forms of mineral fiber insulation have been used at SQN:
- a. Felted mineral fiber flexible blanket type manufactured from resilient refractory fibers, bonded with organic resin and supplied as a.one piece, single layer, wrap-around pipe covering.
- b. Rigid preformed mineral fiber type, manufactured from refractory fibers and with an organic resin binder molded into hollow cylinders, supplied in sections or segments suitable for single or multiple layer pipe covering.
[
Both forms of mineral fiber insulation are applied to straight pipe with metal wire or bands and covered with an .016-inch thick aluminum jacket.
These mineral fiber insulation forms can be characterized as soft because of their relatively low compressive strength compared to certain other types of commonly used pipe insulation such as molded calcium silicate. ASTM Standard C165, " Standard Method for Measuring Compressive Properties of Thermal Insulation" provides procedures for measuring thermal insulation mechanical behavior under compressive load.
' Another of the several mechanical properties which needs to be considered in the selection of insulating material is hardness.
Hardness is defined as that property which measures a material's ability to resist penetration. It affects ease of application and is determined by ASTM Standard C569, " Standard Test Method for Indentation Hardness of Preformed Thermal Insulators." The resilience of the wrap-around blanket type is desirable in some piping applications covering small obstructions such as heat-tracing.
Insulations of all types commonly applied to piping are susceptible to some degree of damage if not handled carefully during installation and protected from abuse af ter installation. Mineral fiber type piping insulation has been widely used in industrial and power plant applications and has provided many years of 00820 12/04/86
! . TVA EMPLOYEE CONCERNS REPORT NUM8ER: 232.3 (8)
-SPECIAL PROGRAM REVISION NUMBER: 1
(
( PAGE 6 0F 11 1
satisfactory service. If damaged during installation or after to the extent that thermal performance is unacceptable, the damaged section of insulation can be economically and readily replaced.
During installation, a reasonable amount of waste from abusive damage and other causes is anticipated and considered acceptable.
Mechanical vibration can cause deterioration of piping insulation j thermal performance through wearing away, settling, or dusting of the insulation material.
The resistance to vib' ration of mineral fiber type piping insulation is good, and there are applications where its mechanical performance-can be superior to that of a harder material such as molded calcium silicate. The microseismic forces resulting from the small amplitude vibrations produced by fluid flow at design i' velocities-in the insulated piping at SQN (and WBN) are not of sufficient magnitude to cause significant wearing away or dusting l
. of the mineral fiber or other insulation used. Furthermore, because of the bonding of the fibers, settling is not a problem with rigid or semirigid insulations.
1 E Satisfactory service experience in widespread applications demonstrates the acceptability of mineral fiber as an economic, l durable and maintainable piping insulation material.
i
- Issue "b"
^
The second concern was received March 12, 1985 by the TVA Nuclear Safety Review Staff (NSRS) during a review of maintenance activities at the SQN plant. The NSRS initiated an investigation to evaluate the validity of the concern by identifying the .
applicable insulation requirements for SQN and the plant's
! compliance with these requirements. The NSRS Investigation Report l
No.1-85-106-SQN, issued December 27, 1985, contained corrective i action recommendations which were completed by the SQN plant staff May 25,1986. The Employee Concern Task Group (ECTG) documented the concern by preparing an Employee Concern Assignment (K-form) on j- September 22, 1986.
, The NSRS investigation revealed the concern pertained to the potential for nonmetallic insulation causing cracking of austenitic
- stainless steel. This possible promotion of stress corrosion
! cracking could arise from contact of austenitic stainless steel l with insulating materials containing excessive levels of leachable 1
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TVA EMPLOYEE CONCERNS REPORT NUMBER: 232.3(B)
SPECIAL PROGRAM REVISION NUMBER: 1 i
! PAGE 7 0F 11
. chloride and fluoride ions as defined in USNRC Regulatory Guide 1.36, " Nonmetallic Thermal Insulation for Austenitic Stainless Steel." Over an extended period of time the concerned individual had observed the installation on safety-related austenitic stainless steel systems of insulation types that he believed were of unacceptable quality (noncompliance with Regulatory Guide 1.36 req uirements) .
In conducting the investigation the NSRS investigator reviewed relevant design drawings and procurement specifications, and interviewed esponsible Office of Engineering (OE) personnel to identify the original SQN plant insulation requirements.
Additionally, plant procurement procedures and standard practices documents were reviewed, and responsible plant personnel were interviewed to determine the extent of insulation replacement due to maintenance and modification activities. Also, the investigator evaluated the traceability of replacement insulation from purchase to installation.
The NSRS Investigation Report No. I-85-106-SQB found that while
( most of the insulating materials installed at SQN were the same as those used at other TVA plants where compliance with Regulatory Guide 1.36 is required, compliance at SQN was uncertain because certification documentation was lacking, and future compliance was not assured. The report appropriately recommended documenting demonstration of compliance with Regulatory Guide 1.36 requirements for nonmetallic insulation installed in the plant and stored on site. It also recommended procedural changes to assure compliance with the Regulatory Guide requirements of future replacement insulation purchased by the plant.
The SQN plant staff response ( App. A, 5.m and 5.n) to the NSRS report recommendations committed to Regulatory Guide 1.36 testing of nonmetallic thermal insulation installed on stainless steel in safety related systems and warehoused in Power Stores, and to maintain testing documentation. Further, the plant response committed to revising SQN plant standard practice SQM35,
" Nonmetallic Thermal Insulation-Austenitic Stainless Steel," to assure that future insulation needs will be procured, stored, and installed in documented compliance with Regulatory Guide 1.36 req ui rements.
00820 12/04/86
o- TVA EMPLOYEE CONCERNS- REPORT NUMBER: 232.3 (B)
SPECIAL PROGRAM REVISION NUMBER: 1 PAGE 8 0F 11 Findings:
a.1 Commercially available mineral fiber type piping insulation has appropriate and economic applications in the SQN plant.
a.2 The general serviceability of mineral fiber piping insulations is satisfactory when installed and maintained with reasonable care.
a.3 At SQN mineral fiber piping insulations exposed to the vibration created by fluid flow in the insulated pipes during normal operation will not experience a significant loss of thermal performance over the long term when installed and maintained in accordance with the manuf acturer's instructions.
b.1 Regulatory Guide 1.36 requirements were recognizea by TVA and all TVA nuclear plants were appropriately instructed in 1975 by Division of Power Production procedure DPM No. N75M9.
b.2 TVA SQN Plant Standard Practice SQM35 (01/18/83) transcribed
(*
the Regulatory Guide 1.36 requirements from DPM No. N75M9 and was incorporated by reference into SQN Plant Procurement Procedure SQA 45, which governed the purchase of replacement insulation at the time of the NSRS investigation but did not require quality certification documentation.
b.3 Subsequent to the NSRS investigation, the SQN plant staff completed a program of testing nonmetallic insulation installed and in Power Stores storage areas which verified and documented compliance with Regulatory Guide 1.36 req uirements.
b.4 The SQN plant staff revised procedure SQM35 to incorporate NSRS report recommendations for documenting compliance with Regulatory Guide 1.36 requirements for new nonmetallic insulation purchases at SQN.
Conclusion:
- a. The Concern is not valid for the mineral fiber types of piping insulation installed at SQN.
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a TVA EMPLOYEE CONCERNS REPORT NUMBER: 232.3 (B)
SPECIAL PROGRAM REVISION NUMBER: 1 PAGE 9 0F 11
- b. The concern was valid for nonmetallic insulation at the time it was raised to the NSRS since the SQN plant could not document compliance with Regulatory Guide 1.36 requirements.
However, subsequent SQN plant actions to revise the insulation procurement procedure and maintain appropriate chemical test documentation now assure and demonstrate the acceptable quality of nonmetallic insulation installed on austenitic stainless steel in safety-related systems. Thus the perceived problem identified by the concern is resolved.
- 10. CORRECTIVE ACTION:
No corrective action is required.
,e i
I i
A.
00020 12/04/06 l.
- i TVA EMPLOYEE CONCERNS REPORT NUMBER: 232.3(B)
SPECIAL PROGRAM REVISION NUMBER: 1
( PAGE 10 0F 11 APPENDIX A S. DOCUMENTS REVIEWED RELATED TO THE ELEMENT:
I
- a. TVA Mechanical Design Guide DG-M18.9.1, " Insulation for Piping and Equipment in Nuclear Power Plants"
- b. TVA Design Criteria, SQN-DC-V-2.10, " Insulation used Within the Containment Vessel"
- c. TVA Design Criteria, SQN-DC-V-1.1.ll.4, " Pipe Insulation Modifications for Pipe Rupture Protection Outside Containment"
- d. TVA Specification No.1475, " Thermal Insulation Materials for Piping and Equipment Inside the Containment for Sequoyah Nuclear Plant Units 1 and 2 and Thermal Insulation Materials for Piping, Equipment and Reactor Vessel Inside the Containment for Watts Bar Nuclear Plant Units 1 and 2"
- e. TVA Specification No. 2093, " Insulation for Piping and p Equipment Including Installation, and Pipe and Equipment
, Insulation Installation Inside Containment and the Main and Reheat Steam Piping to the Turbine Building, Sequoyah Nuclear Plant Units 1 and 2"
- g. FIBREX Inc. Technical Data Sheet for "Epitherm 1200 Molded i Pipe Insulation"
- h. Forty Eight Insulations Inc. Product Data Sheet for
" Forty Eight MF Pipe Insulation"
- 1. ASTM Standard Specification C547-77 for " Mineral Fiber Preformed Pipe Insulation"
- j. ASTM Standard Specification C592-80 for " Mineral Fiber Blanket Insulation and Blanket-Type Pipe Insulation (Metal-Mesh Covered) (Industrial Type)"
i l k. Letter from L. M. Mills, TVA, to A. Schwencer, NRC, No. A27 800721018, (07/21/80)
- 1. TVA Nuclear Safety Review Staff Investigation Report No.
I-85-106-SQN,(12/27/85) 00820 12/04/86
'* TVA EMPLOYEE CONCERNS REPORT NUMBER: 232.3 (B)
SPECIAL PROGRAM REVISION NUMBER: 1
( PAGE 11 0F 11 APPENDIX A (Cont'd)
- m. TVA memorandum from H. L. Abercrombie to K. H. Whitt, (01/16/86)
- n. TVA memorandum from K. H. Whitt to H. L. Abercrombie (02/13/86)
" Nonmetallic Thermal Insulation - Austenitic Stainless Steel" L
- 6. WHAT REGULATIONS, LICENSING C0091ITMENTS, DESIGN REQUIREMENTS, OR OTHER APPLY OR CONTROL IN THIS AREA 7
- a. SQN plant design criteria listed in 5.b above
- d. USNRC Regulatory Guide 1.36, " Nonmetallic Thermal Insulation for Austenitic Stainless Steel"
" Nonmetallic Thermal Insulation for Austenitic Stainless Steel"
" Nonmetallic Thermal Insulation - Austenitic Stainless Steel"
- 7. LIST REQUESTS FOR INFORMATION, MEETINGS, TELEPHONE CALLS, AND OTHER DISCUSSIONS RELATED TO EttMtMI.
- d. Telecon between Mahlman and Mills, TVA Knoxville, and Griffith, Bechtel SF, (09/24/86)
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128 FREQUENCY - REQUEST OFFICE OF NUCLEAR POWER RUN TIME - I2:57:19 I ONP - 1555 - RAM EMPLOYEE CONCERN PROGRAM SYSTEM (ECPS) RUN DATE - 12/02/86 LIST OF EMPLOYEE CONCERN INFORMATION CATEGORY: EN DES PROCESS & OUTPUT SUBCATEGORY: 25205 INCORRECT PIPING INSULATION MATERIAL I S GENERIC KEYWORD A H APPL QTC/NSRS P KEYNORD B CONCERN SUB R PLT BBSH INVESTIGATION S CONCERN KEYWORD C NUMBER CAT CAT D LOC FLQB REPORT R DESCRIPTION KEYHORD D
) NONCONFORMANCE EX 089-002 EN 23205 N HBN YYYY SR CI FEELS THAT IMPROPER INSULATION MA T50192 K-FORM TERIALS HERE INSTALLED IN MANY ASPEC CORRECTIVE ACTION TS OF H5HP CONSTRUCTION. CI EXPRESS CONSTRUCTION 3 ED THAT MOST OF THE INSULATION INSTA INSULATION LLED HAS "SOF" INSULATION (" ROCK H00 L"), COVERED BY A METAL SHEATH. CI STATED THAT THIS TYPE OF INSULATION
) IS EASILY DAMAGED. AND IS SUBJECT TO DETERIORATION DUE TO VIBRATION OVER LONG PERIODS OF TIME. CI EXPRESSED THAT A " HARDER" TYPE OF INSULATION
) SHOULD HAVE BEEN USED. NUC. POWER D EPT. CONCERN. CI HAS NO FURTHER INF ORMATION.
3 I-85-106-SQN EN 23203 N SQN YYYY SR THE EMPLOYEE HAS CONCERNED ABOUT THE K-FORM QUALITY OF NONMETALLIC THERMAL INSU LATION BEING INSTALLED ON AUSTENITIC STAIHLESS STEEL SAFETY-RELATED SYST I EMS. HE STATED THAT IN PAST EXPERIEN CE AT OTHER NUCLEAR PLANTS THE TYPES OF INSULATION THAT TVA IS USING AT SEQUOYAH HOULD NOT BE ACCEPTABLE. HE
-) STATED THAT HE HAD QUESTIONED THE U SE OF THESE TYPES OF INSULATION ABOU T TH0 YEARS PRIOR TO THE PLANT STAFF AND HAD BEEN TOLD THAT EVERYTHING H AS OK. HE HAS LOOKING FOR AN INDEPEN DENT ACCESSMENT.
2 CONCERNS FOR CATEGORY EN SUBCATEGORY 23203
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