05000272/LER-2016-001, Regarding Unanalyzed Condition Due to Degraded Reactor Baffle to Former Bolts
| ML16187A330 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 07/05/2016 |
| From: | Carr E Public Service Enterprise Group |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LR-N16-0126 LER 16-001-00 | |
| Download: ML16187A330 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(x) 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(i) |
| 2722016001R00 - NRC Website | |
text
LR-N16-0126 JUL 0 5 2016 PSEG Nuclear LLC P.O. Box 236, Hancocks Bridge, NJ 08038-0236 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001
SUBJECT:
Salem Nuclear Generating Station Unit 1 Renewed Facility Operating License No. DPR-70 NRC Docket No. 50-272 LER 272/2016-001-000 10 CFR 50.73 Unanalyzed Condition due to Degraded Reactor Baffle to Former Bolts Licensee Event Report, "Unanalyzed Condition due to Degraded Reactor Baffle to Former Bolts" is being submitted pursuant to 10 CFR 50.73 (a)(2)(ii)(B), "The nuclear power plant being in an unanalyzed condition........ "
Should you have any questions or comments regarding the submittal, please contact Mr. Thomas Cachaza of Regulatory Affairs at 856-339-5038.
There are no regulatory commitments contained in this letter.
Sincerely, Eric Carr Plant Manager Salem Generating Station tjc Enclosure-LER 272/2016-001-000
Page 2 10 CFR 50.73 LR-N16-0126 cc Mr. D. Dorman, Administrator-Region 1, NRC Ms. C. Parker, Licensing Project Manager-Salem, NRC Mr. P. Finney, USNRC Senior Resident Inspector, Salem (X24)
Mr. T. Cachaza, Salem Commitment Tracking Coordinator Mr. L. Marabella, Corporate Commitment Tracking Coordinator
NRC FORM 366 (11-2015)
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- 1. FACILITY NAME U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LER)
(See Page 2 for required number of digits/characters for each block)
Salem Generating Station - Unit 1
- 4. TITLE APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2018
, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 2. DOCKET NUMBER
- 3. PAGE 05000272 1 OF 3 Unanalyzed Condition due to Degraded Reactor Baffle to Former Bolts
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED I
SEQUENTIAL I REV FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR MONTH DAY YEAR NUMBER NO.
05000 FACILITY NAME DOCKET NUMBER 05 03 2016 2016-001
- - 000 07 05 2016 05000
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
D 20.22o1(b)
D 20.2203(a)(3)(i)
- 50. 73(a)(2)(ii)(A)
- 50. 73(a)(2)(viii)(A) 20.2201 (d) 20.2203( a)(3)(ii)
M 50. 73( a)(2)(ii)(B) 50.73( a)(2)(viii)(B)
Defueled 20.2203(a)(1) 20.2203( a)( 4)
- 50. 73( a)(2)(iii)
- 50. 73(a)(2)(ix)(A) 0 20.2203(a)(2)(i)
D 50.36(c)(1 )(i)(A)
D 50.73(a)(2)(iv)(A)
D 50.73(a)(2)(x)
- 10. POWER LEVEL 0 20.2203(a)(2)(ii) 0 50.36(c)(1)(ii)(A)
D 50.73(a)(2)(v)(A)
D 73.71(a)(4) 0 20.2203(a)(2)(iii) 50.36( c )(2)
D 50.73(a)(2)(v)(B) 73.71(a)(5) 20.2203(a)(2)(iv) 50.46(a)(3)(ii) 50.73(a)(2)(v)(C) 73.77(a)(1)
Oo/o C 20.2203(a)(2)(v) 0 50.73(a)(2)(i)(A)
- 50. 73( a)(2)(v)(D) 73.77(a)(2)(i)
C 20.2203(a)(2)(vi) 50.73(a)(2)(i)(B) 0 50.73(a)(2)(vii)
D 73.77(a)(2)(ii) 50.73(a)(2)(i)(C)
OTHER Specify in Abstract below or in
CAUSE OF EVENT
APPROVED BY OMB: NO. 3150-0104 EXPIRES: 01/31/2018
, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 6. LER NUMBER I
SEQUENTIAL NUMBER YEAR 2016 001 I REVISION NUMBER
- - 000
- 3. PAGE 3
OF3 The failure mechanism of the described bolting is identified as irradiation assisted stress corrosion cracking (IASCC), a known industry issue that is inherent within designs that utilize Westinghouse-supplied stainless steel Type 347 baffle to former bolting.
Exposure to high levels of fast neutrons results in embrittlement of the stainless steel bolting, evidenced by an increase in tensile strength and a decrease in ductility. As residual ductility is further reduced and embrittlement progresses, additional stresses via neutron irradiation can result in the formation and propagation of cracks. IASCC is a time related degradation that is associated to the operating life of the components. The significant factors that contribute to the initiation and propagation of IASCC degradation are neutron fluences, time of operation, fatigue inducing loading cycles on the baffle plates, pressure differentials across the baffle plates, and temperature. Failure analysis of selected removed bolts will be performed to confirm this cause.
SAFETY CONSEQUENCES AND IMPLICATIONS
Westinghouse performed an evaluation, which is based on sound engineering assumptions, concludes that Salem Unit 1 met the requirements for core coolability and safe shut-down in its "as-found" state during 1 R24, considering both potential baffle bolt failures due to a LOCA and loose parts from degraded baffle-former bolts found during 1 R24. On this basis, safe operation and safe shutdown of Salem Unit 1 was assured during Cycle 24.
SAFETY SYSTEM FUNCTIONAL FAILURE This event is not being reported as a safety system functional failure.
Westinghouse performed an evaluation, which is based on sound engineering assumptions, concludes that Salem Unit 1 met the requirements for core coolability and safe shut-down in its "as-found" state during 1 R24, considering both potential baffle bolt failures due to a LOCA and loose parts from degraded baffle-former bolts found during 1 R24. On this basis, safe operation and safe shutdown of Salem Unit 1 was assured during Cycle 24.
PREVIOUS EVENTS A review of previous events for the past three years identified no similar events.
CORRECTIVE ACTIONS
Salem is taking the following actions:
The degraded baffle to former bolts are being replaced.
Failure analysis of selected removed bolts will be performed to confirm IASCC as the cause.
An acceptable bolting pattern analysis was performed to determine the required bolting replacement scope.
Required bolting was replaced for one cycle of operation while also relying on original baffle-former bolts that had no UT indications
COMMITMENTS
There are no regulatory commitments contained in this LER.