ML20213E873

Safety Evaluation Supporting Util 861002 Request for Relief from Inservice Insp Requirements of ASME Code Section XI Re Peripheral CRD Housings

ML20213E873
Person / Time
Site:	Calvert Cliffs
Issue date:	05/11/1987
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20213E786	List: ML20213E784 ML20213E873
References
NUDOCS 8705150171
Download: ML20213E873 (5)

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- NUCLEAR

• REGULATORY COMMISSION WASHINGTON, D. C. 20555

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION-BALTIMORE GA5 & ELECTRIC COMPANY CALVERT CLIFF 5 NUCLEAR POWER PLANT, UNITS 1 AND 2 DOCKET N05. 50-317 AND 318 RELIEF FROM INSERVICE INSPECTION REOUIREMENTS OF SECTION XI 0F THE ASME CODE

1.0 INTRODUCTION

i The Technical Specifications for the Calvert Cliffs Units 1 and 2 require that inservice examination of ASME Code Class 1, 2 and 3 components shall

. be performed in accordance with Section XI of the ASME Code as required by 10 CFR 50.55afg)(4) except where specific written relief has been granted by the Commission. Some plants were designed in conformance to early editions of this Code Section, consequently certain requirements of later editions and addenda of Section XI are impractical to perform because of the plant's design, component geometry, and material of construction. Paragraph 10 CFR 50.55a(g)(6)(1) authorizes the Commission to grant relief from those requirements upon making the necessary findings.

In a letter dated October 2,1986, as supplemented December 4,1986, the Baltimore Gas & Electric Company (BG&E), the licensee, identified specific ASME Code reauirements that BG&E determihad to be imoractical to perform at Calvert Cliffs and requested relief from these requirements.

The staff has evaluated the licensee's supporting technical justification and finds it to be acceptable.

2.0 EVALUATION OF RELIEF RE0 VESTS The licensee requested relief from specific inservice inspection (ISI) requirements and provided supporting technical information. The staff reviewed this information as related to the existing design, geometry and materials of construction of the components.

A.

Relief Request No. 1, Examination Categories B-G-1, B-G-2 and C-D, ASME Code Class 1 and 2 Bolting.

Code Requirements: ASME Section XI, 1974 Edition including Addenda through Sumer 1975, requires the following:

1. Class 1 Bolting (a) B-G-1 Volumetric examination is required on pressure-retaining bolting that is 2 inches and larger in diameter.

(b) B-G-2 Visual examination is rwuired for pressure-retaining bolting that is smaller than 2 inches in diameter.

I 11 Dohk &S50317 PDR

2. Class 2 Bolting: .

C-D Visual and either surface or volumetric examina-tions are required for pressure-retaining bolting exceeding 1 inch in diameter.

Code Relief Request: The licensee proposed to meet the require-ments of the 1977 Edition of Section XI and later editions and addenda of ASME Section XI, in which Examination Categories B-G-1, B-G-2 and C-D are redefined. Category B-G-1 is redefined as pressure-retaining Class 1 bolting, larger than 2 inches in diameter. Category B-G-2 is redefined as pressure-retaining Class 1 bolting, 2 inches and smaller in diameter. Bolting that is exactly 2 inches in diameter is shifted from Category B-G-1 to B-G-2. Similarly, Category C-D is redefined as pressure-retaining Class 2 bolting exceeding 2 inches in diameter. The licensee proposed to adopt the definitions set forth in the later editions and addenda of Section XI Code to define the boundaries for Categories B-G-1, B-G-2 and C-D.

Basis for Relief Later editions and addenda of the Section XI Code are approved for use, as per paragraph (g) of 10 CFR 50.55a of the Code of Federal Regulations. Paragraph g(4)(iv) allows the adoption of portions of later approved editions and addenda to the Code provided that all related requirements of the respective editions and addenda are met. The licensee feels that the above stated adoptions are in compliance with the stated regulations.

Staff Evaluation Paragraph 10 CFR 50.55a(g)(4)(iv) states: " Inservice examinations of components, tests of pumps and valves, and system pressure tests, may meet the requirements set forth in subsequent editions and addenda that are incorporated by reference in paragraph (b) of this section, subject to the limitations and modifications listed in paragraph (b) of this section and subject to Comission approval. Portions of editions or addenda may be used provided that all related requirements of the respective editions or addenda are met."

The licensee intends to use provisions from the 1977 and later approved Section XI ASME Code editions and addenda. Even though the extent and method of examinations have been reduced, other licensees with ISI programs based on the later ASME Code documents are following these requirements pursuant to 10 CFR 50.55a(g)(41 The staff has determined that the licensee's proposal confonns to the requirements of the regulation that "all related requirements

of the respective editions or addenda are met." Therefore, the staff concludes that the licensee's proposal is acceptable.

B. Relief Request No. 2, Examination Category B-0, Peripheral Control Rod Drive Housings Code Requirements: Article IWB-2600 of ASME Section XI, 1974 Edition including Addenda through Summer 1975 requires a volumetric examination to include 100% of the welds in 10% of the peripheral control rod drive (CRD) housings during each inspection interval.

Code Relief Request: In the October 2, 1986 submittal, the licensee proposed to meet the requirements of Article IWB-2600 of the 1977 Edition of Section XI and later editions and addenda of the Section XI Code, which require surface or volumetric examination of 100% of the welds in 10% of the peripheral CRD housings. The licensee proposed to perfonn surface examinations, as per later editions of the code, rather than volumetric examinations.

On December 4,1986, the licensee modified this relief request after detennining that these requirements were impractical due to difficulties experienced in the perfonnance of the surface examinations on the Unit I peripheral CRD housings, lhere are 28 peripheral CRD housings in the installed configuration.

After removal of the reactor vessel (RV) head shroud and insulation, the licensee attempted to inspect 100% of the welds on three peripheral CRD housings and detennined that only part of the CRD housing welds could be examined as the welds extend into the RV head itself.

An alternative CR0 housing surface examination was conducted by inspecting 75% of the welds on three CR0 housings and 50% of the welds on two CRD housings.

Basis for Relief (1) Later editions and addenda of the Section XI Code are approved for use, as per paragraph (g) of 10 CFR 50.55a of the Code of Federal Regulations. Paragraph g(4)(iv) allows the adoption of portions of later approved editions and addenda to the code provided that all related requirements of the respective editions and addenda are met. The licensee feels that the above stated adoptions are in compliance with the stated regulations.

(2) Volumetric examination of these welds is inpractical due to design configuration, accessibility and materials of construction as described in CE Drawing No. 233-412, Weld Details, which'has been provided to the staff.

(a) Ultrasonic examination will not provide meaningful results due to the geometeric configuration of the joint and mater-ial properties (inconel-to-stainless steel welds).

(b) Radiographic examination cannot be performed due to the design configuration and accessibility.

(3) Proposed alternatives to the requirements of Section XI of the ASME Code which are determined to be impractical, may be permitted by 10 CFR 50.55a(g)(6)(1) if the proposed alternatives are detemined to be authorized by law and will not endanger life or property or the comon defense and security and is otherwise in the public interest giving due consideration to the burden upon the licensee that could result if the requirements were imposed on the facility.

Staff Evaluation The licensee's letter of October 2,1986 proposes to use provisions from the 1977 and later approved Section XI ASME Code editions and addenda. The staff has determined that this pro with the requirements of 10 CFR 50.55a(g)(4)(iv)posal does conform that " portions of editions or addenda may be used provided that all related requirements of the editions or addenda are met."

In addition, the staff has determined that the requirement to examine 100% of the welds on three peripheral CRD housings is impractical due to the physical constraints of the installed configuration of the housings and the reactor vessel head. The alternative examination method as proposed in the licensee's De,cember 4,1986 submittal has been detemined to oe acceptable pursuant to 10 CFR 50.55a(g)(6)(i) and contingent upon the licensee's performance of 100% weld examinations on the peripheral CRD housings in the event this examination is feasible (e.g., if the CRD housing is physically removed from the reactor vessel head). This contingency i shall be applicable to all future 10-year inservice inspection intervals for each unit.

3.0 CONCLUSION

The staff has completed the review of the licensee's letters dated October 2, 1986 and December 4,1986 based on the provisions of 10 CFR 50.55afgM6)(i).

The staff concludes that the licensee's proposal to update to the 1977 l Section XI requirements of the ASME Code for Class 1 and 2 boltina and CRD housings meets the provisions of 10 CFR 50.55a(g)(4)(iv), is acceptable, l

l and therefore, the licensee shall be granted relief to update to the requirements of the 1977 and later editions and addenda of Section XI of the ASME Code for the Class 1 and 2 bolting and the CRD housing

examinations. In addition, the staff has detemined that the'1977 ASME Code (and 1974 ASME Code, too) requirement to examine 100% of the welds on three peripheral CRD housings is impractical and that this relief shall be granted contingent upon the perfomance of these 100% CRD housing weld inspections when physically possible. This granting of relief is authorized by law and will not endanger life or property or the connon defense and security and is otherwise in the public interest, considering the burden that could result if these ASME Code Section XI requirements for the CRD housing examinations were imposed on the facility. Therefore, in accordance with 10 CFR 50.55a(g)(6)(1), this relief is granted.

Date: May 11, 1987 Principal Contributors:

M. Hum, S. McNeil l

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