ML18065A718
| ML18065A718 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 05/09/1996 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML18065A717 | List: |
| References | |
| NUDOCS 9605170305 | |
| Download: ML18065A718 (6) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION OF THE THIRD IO-YEAR INTERVAL INSERVICE INSPECTION PROGRAM PLAN REQUEST FOR AUTHORIZATION TO IMPLEMENT CODE CASE N-533 I. 0 INTRODUCTION FOR CONSUMERS POWER COMPANY PALISADES NUCLEAR PLANT DOCKET NO~ 50-255 The Technical Specifications for Palisades Nuclear Plant state that the inservice inspection (ISI) of the American Society of Mechanical Engineers (ASME} Code Class I, 2, and 3 components shall be performed in accotdance with Section XI -0f the ASME Boiler and Pressure Vessel Code and *applicable Addenda as required by IO CFR 50.55a(g), except where specific written relief has been granted by the Cammi ss ion pursuant to IO CFR 50. 55a ( gH6 )( i). Paragraph '
50.55a(a)(3) of IO CFR states that alternatives to the requirements of paragraph ( g) may be used, when authorized by the NRC, if* ( i) the proposed alternatives would provide an acceptable level -Of quality and safety or (i.i) compliance with the spectfied requirements would result in hardship or unusual difficulties without a compensating increase in the'level of quality and safety..
Pursuant to IO CFR 50.55a(g)(4), ASME Code Class I, *2, and 3 components (including supports) shall meet the requirements, except the design and access provisions and the preservice examination requirements, set forth in the ASME Code,Section XI, "Rules for Inservice Inspection of Nuclear Power Plant Components," to the extent practical within the limitations of design,
. geometry, and materials of construction of the components.
The regulations require that inservice examination of components and system pressure tests conducted during the first IO-year interval and subsequent intervals comply W*ith the requirements in the latest edition and addenda of Section XI of the ASM~ Code incorporated by reference in IO CFR 50.55a(b) I2 months prior to the start of the I20-month interval, subject to the limitations and modifications listed therein. The applicable edition of Section XI of the ASME Code for the Palisades Nuclear Plant third IO-year ISi interval is the 1989 Edition.
The components (including supports) may meet the requirements set forth in subsequent editions and addenda of the ASM~ Code incorporated by reference in IO CFR 50.55a(b) subject to the limitation~ and modifications listed therein and subject to Commission approval.
Pursuant to IO CFR 50.55a(g)(5), if the licensee determines that conformance with an examination requirement of Section XI of the ASME Code is not practical for its facility, information shall be submitted to the Commission in support of that determination and a request made for relief from the ASME
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- Code requirement. After evaluation of the determination, pursuant to IO CFR 50.55a(g)(6)(i}, the Commission may grant relief and may impose alternative requirements that are determined to be authorized by law, will not endanger life, property, or the common defense and security, and are otherwise in the public interest, giving due consideration to the burden upon the licensee that could result if the requirements were imposed.
In a letter dated January IS, I996, Consumers Power Company submitted to the NRC its third IO-year interval ISi program plan request to implement Code Case N-533,
"*Alternative Requirements for VT-2 Visual Examination of Class 1 Insulated Pressure-Retaining Bolted Connections,Section XI, Division l," as an alternative to the Code requirements for Palisades Nuclear Plant.
2.0 EVALUATION AND CONCLUSIONS *.
The staff, with techn.ical assistance from its contractor, the Idaho National Engineering Laboratory (INEL}, has evaluated the information provided by the licensee in support of its request to implement Code Case N-533, "Alternative Requirements for VT-2 Visual fxamination of Class 1 Insu'lated Pressure-Retaining Bolted Connections~ Section.XI, Division 1," as an alternative to the Code requirements for Palisades Nu~lear Plant.
Based on the information submitted, the staff adopts the contractor's conclusions and recommendations presented in the Technical Letter Report attached. The staff has concluded that by implementing Code Case N-533 the...
licensee will be able to locate and evaluate leakage, or evidence of Jeakage,
- in a manner comparable to following the requirements of the Code, and thus: the licensee's proposed alternative provides an acceptable level of quality and safety. Therefore, the licensee's proposed alternative to implement Code Case N-533 is authorized pursuant to 10 CFR 50.55a(a)(3)(i}, provided a 4-hour hold time at test conditions is observed prior to the VT-2 visual examination; The use of this Code Case is authorized for Palisades Nuclear Plant for the third IO-year ISi interval or until the Code Case is approved for general use by reference in Regulatory Guide l.I47, 11 Inservice Inspection of Code Case
- Acceptability, ASME Section XI, Divisio~ l." After that time, the li~ensee may continue to use Code Case N-533 with the limitations, if any,,listed in the regulatory guide.
Attachment:
Technical Letter Report Principal *Contributor: T. Mclellan
- oate:
May 9, 1996
TECHNICAL LETTER REPORT
- ON THE THIRD 10-YEAR INSERVICE INSPECTION INTERVAL REQUEST FOR AUTHORIZATION TO USE CODE CASE N-533 FOR
1.0 INTRODUCTION
CONSUMERS POWER COMPANY PALISADES NUCLEAR PLANT DOCKET NUMBER:
50-255 By letter dated January 18, 1996, the licensee, Consumers Power Company, submitted a request for authorization to use Code Case N-533 at Palisades Nuclear Plant.
The Idaho National Engineering Laboratory (INEL) staff has evaluated this request in the following section.
- 2. 0 EVALUATION The Code of record for the Palisades Nuclear Plant third 10-year inservice inspection interval, which began May 12, 1995, is the 1989 Edition of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code,Section XI.
The information provided by the licensee in support of the request for relief from Code requirements has been evaluated and t~e basis for disposition is documented below.
Request for Authorization to Use Code Case N-533. Alternative Requirements for VT-2 Visual Examination of Class 1 Insulated Pressure-Retaininq Bolted Connections.Section XI. Division 1 Code Requirement~ IWA-5242(a) states that for systems borated for th&
purpose of controlling reactivity; insulation shall be removed from pressure~retaining bolted.connections for *a direct VT-2 visual
- examination.
Code cases are periodically published.by ASME to either clarify the intent of the Code rules or to provide_ alternatives to existing Code requirements.
Use of these.nonmandatory Code cases for inservice Attachment to NRC SE datedMay 9, 1996
- inspection is subject to general acceptance by the NRC staff and incorporation into Regulatory Guide 1.147.
Pursuant to 10 CFR 50.55a, other Code cases may be used provided specific authorization is granted.
Licensee's Code Relief Request:
The licensee has requested authorization to use Code Case N-533, Alternative Requirements for VT-2 Visual Examination of Class 1 Insulated Pressure-Retaining Bolted Connections,Section XI, Division 1.
Lice~~ee's Basis.for Requesting Relief (as stated):
"When the plant is at hot shutdown, a system pressure test and VT-2 visual examination will be completed with insulation installed on bolted connections.
This test and examination philosophy is consistent with the Inservice Inspection Pressure Test Program which was in place during the second ISi interval.
Thes~ examinations, in conjunction with routine monitoring of Primary Coolant System (PCS) leakage, will provide adequate assurance of PCS integrity.* The significant burden imposed by examination of hot, uninsulated components and subsequent reinsulation is not commensurate with their marginal contribution to plant safety.
The proposed alternative will reduce exposure to personnel hazards, s~ch
.as, heat stress, elevated work areas, and radiation environments.
Conduct of examinations and installation of insulation during hot conditions would require examiners to access ~quipment which is operating at approximately 500°F, exposing examiners to heat stress and burn hazards. Additionally, examination of the Primary Coolant System (PCS)*
and Engineered Safeguards System (ESS} bolted connections would require access to the Containment Building when floor plugs have been removed for operation exposing examiners to elevated work area hazards.
Additional dose would be accumulated and examination efficiency would be decreased due to the necessity to wear special protective.equipment (eg, ice vest) and to-limit stay fimes in hot environments.
The proposed alternative will take advantage of outage activities which,
. by their nature, result in disassembly and restoration of bolted
'*connections.
The proposed alternative will allow examination to take place during the course of these outage activities and avoid redundant efforts.
By avoiding redundant efforts, plant resources can.be used to complete other safety significant tasks."
- (icensee's Proposed Alternative Examination {as stated):
"Following opening and reclosing of components in the PCS the following alternative requirements will be met in lieu of the requirement of IWA-5242{a) to remove insulation from Class I pressure retaining bolted connections to perform a VT-2 visual examination.
I.
A system pressure test and VT~2 visual examination shall be performed each refueling outage without insulation removal.
- 2.
Each refueling outage the insulation shall be removed from the bolted connection, and.a VT-2 visual examination shall be performed.
The connection is not required to be pressurized.
Any ~vidence of leakage shall be evaluated in accord~nce with IWA-5250.
These requirements are specified in Nuclear Code Case N-533 as approved by the Board of Nuclear Codes and Standards."
Evaluation:
Paragraph IWA-5242{a) requires the re~oval of all insul~tion from pressure-retaining bolted connections in systems borated for the purpose of controlling reactivity when performing VT-2 visual examtnations during system pressure tests. The li~ensee has.proposed to use Code Case N-533, which requires I) performance of the Code-required pressure test without removing th~ insulation, 2) examination of Class I bolted connections, each refueling out~ge, at atmospheric or static pressure with th~ insulatio~ removed, and 3) evaluation of any evidence of leakage in accordance with IWA-.5250.
Paragraph IWA-5242{a) provides requirements for detecting leakage or evidence of ieakage at bolted connections.
Perfonni_ng 'a VT-~ visual examination during system pressure tests, as required by Code Case N-533, with the insulation in place will likely result in the detection,of any significant leakage, provided a four-hour hold time i.s observed prior to the VT-2 visual examination.
Furthermore, perfonning a VT-2 visual examination after removal of the insulation at atmospheric or static
- pressure during outages, as specified by Code Case N-533, will allow examination* for*eyidence of borated water leakage.
Evidence of leakage will be evaluated in accordance with IWA-5250 of Section XI.
- It is the opinion of the INEL staff that by following Code Case N-533 the licensee will locate and evaluate leakage, or evidence*of leakage, in a manner comparable to the requirements of the Code, and thus provides an acceptable level of quality and safety. Therefore, it is recommended that the licensee's proposed alternative be authorized pursuant to 10 CFR 50.55a{a)(3)(i), provided a four-hour hold time at test conditions is observed prior to the VT-2 visual examination.
3.0 CONCLUSION
The INEL staff has reviewed the licensee's submittal and *concluded that by using Code Case N-533 the licensee will locate and evaluate leakage, or evidence of leakage, in a manner comparable to following the
. requirements of the Code; and thus the licensee's proposed_ alternative provides an acceptable level qf quality and safety. Therefore, it is recommended that the licensee's proposed alternative, to implement Code
- case N-533, be authorized pursuant to 10 CFR 50.55a(a)(3)(i), provided a four-hour hold time at test conditions is ~bserved prior to the vi-2 visual examination.
The *use of this Code Case should be authorized for Palisades Nuclear Plant until the Code Case is approved for general use by reference in Regulatory Guide 1.147. After that time, the licensee may ~ontinue to use Cod~ Case N-533 with the limitations, if any, listed in Regulatory Guide 1.147.