05000282/LER-2002-001, Condition Prohibited by Technical Specifications Due to Potential Auxiliary Building Special Vent Zone Boundary Degradation
| ML022680158 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 09/16/2002 |
| From: | Nazar M Nuclear Management Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LER 02-001-00 | |
| Download: ML022680158 (7) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(ix)(A) 10 CFR 50.73(a)(2)(x) 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2) |
| 2822002001R00 - NRC Website | |
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I Committed to Nuoear Ex ce September 16, 2002 Mano K. Nazar Site Vice President Prairie Island Nuclear Generating Plant Nuclear Management Company, LLC 1717 Wakonade Dr. East
- Welch MN 55089 10 CFR 50.73 U S Nuclear Regulatory Commission Aftn: Document Control Desk Washington, DC 20555 PRAIRIE ISLAND NUCLEAR GENERATING PLANT Docket Nos. 50-282 License Nos. DPR-42 50-306 DPR-60 LER 1-02-01: Condition Prohibited By Technical Specifications Due to Potential For Auxiliary Building Special Vent Zone Boundary Degradation The Licensee Event Report for this occurrence is attached. In the report, we made no new NRC commitments. Please contact us if you require additional information related to this event.
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Mano K. Naz Site Vice Pr ent Prairie Islan uclear Generating Plant c:
Regional Administrator-Region lll, NRC NRR Project Manager, NRC Senior Resident Inspector, NRC James Bernstein, State of Minnesota Attachment
NRC FORM 366 U.S. NUCLEAR REGULATORY APPROVED BY OMB NO. 3150-0104 EXPIRES 630-2001 (1-2001)
COMMISSION
, the NRC may not conduct or sponsor, and a person is not required to respond to, the Information collection FACILITY NAME (1)
DOCKET NUMBER (2)
PAGE (3) 05000 282 Prairie Island Nuclear Generating Plant Unit 1 I
OF 6
TITLE (4)
Condition Prohibited by Technical Specifications Due to Potential Auxiliary Building Special Vent Zone Boundary Degradation EVENT DATE 5)
LER NUMBER (6)
REPORT DATE 17 l
OTHER FACILITIES INVOLVED (8)
FACILITY NAME OCKET NUMBER MO DAY YEAR YEAR NUMBR NO MO DAY YEAR Prairie Island Unit 2 05000 306 07 16 02 02 01
- - 00 09 16 02 FACILITY NAME DOCKET NUMBER OPERATING 1
THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 Cl R § (Check all that apply) (11)
MODE (9) 20 2201(b)
_ 20 2203(a)(3 (ii) 50 73(a)(2)(ii)(B)
I 50.73(a)(2)(ix)(A)
POWER 100 1 20 2201(d)
_ 20.2203(a)(4)
_ 50 73(a)(2)(in)
I 50.73(a)(2)(x)
LEVEL (10) 20.2203(a)(1)
_ 50 36(c)(1)(i)(A)
_ 50.73(a)(2)(iv)(A) 73.71(a)(4) 6 20 2203 a (2
)
50 36 C (1)(ii)(A) 5073 a (2 )vA(A) 73 71(a)(5) 20.2203 a)
C I 50.73 a(2) v OTHER a20 2203 a
2 ii 50 46 a
V pci n Abstract below or in
- - 2 25073a Vii 20 2203 a 3Q a
a ii50.7 a2 20 2203(a(3)(a
)
50.73(a)(1 1)(A) 50.73(a)(2)(viin)(B)
LICENSEE CONTACT FOR THIS LER (12)
NAME ATELEPHIONE NUMBER (Include Area Code)
Robert
_________Alexander________________
651-388-1121 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13) l I MANU-I REPORTABLE I,
MANU-REPORTABLE
CAUSE
l SYSTEM l COMPONENT FACTURER l
TO EPIX I A CUSE SYSTEM I COMPONENT I
It t
SUPPLEMENTAL REPORT EXPECTED (14)
EXPECTED MONTH DAY YEAR YES (If yes, complete EXPECTED SUBMISSION DATE).
I X INO DATE (15) l ABSTRACT (Limit to 1400 spaces, Le, approximately 15 single-spaced typewritten lines) (16)
Prairie Island Technical Specification 3.6.E.2 states that; "Openings in the Auxiliary Special Ventilation Zone are permitted provided they are under direct administrative control and can be reduced to less than 10 square feet within 6 minutes following an accident".
On July 16, 2002, while both units were operating at 100% power, a potential uncontrolled Auxiliary Building Special Vent Zone (ABSVZ) boundary leakage path was identified. Upon discovery of the potential deficiency, the doors from the "Hot" Chemistry Lab to the ABSVZ were treated as openings in the boundary and were placed under administrative controls as allowed by the Technical Specifications.
The cause of the event is attributed to design changes that were performed during plant construction in 1973, which realigned "Hot" Chemistry Lab ventilation supplies and failed to recognize the potential effect on the ABSVZ boundary.
Future design changes or continued use of administrative controls are being evaluated as corrective actions to resolve this issue.
No equipment failures occurred during this event.
NRC FORM 366 (1-2001)
(If more space is required, use additional copies of (If more space is required, use additional copies of (if more space is required, use additional copies of (If more space is required, use additional copies of (If more space is required, use additional copies of NRC Form 366A) (17)
Therefore, the ABSVZ and the ABSV system would have been capable of mitigating the affects of a LOCA and of maintaining the predicted dose to off-site and control room personnel within the previous predicted values in the post-LOCA dose analyses.
Impact on Safety Significance Functional Failure Performance Indicator The consideration in this case is whether the as-found configuration, by itself, could have resulted in a loss of the ABSV system safety function. As noted above, using the as-found leak rate test results of the past three years, even if the ABSV system was assumed to not be able to maintain negative pressure in the Auxiliary Building, the offsite and control room dose limits would not be exceeded.
CORRECTIVE ACTIONS
Immediate Actions Taken Upon discovery of the potential deficiency, the doors from the "Hot" Chemistry Lab to the remainder of the ABSVZ were treated as potential openings in the ABSVZ boundary, and as a compensatory measure, were placed under administrative controls in accordance with existing administrative guidance as allowed by the Technical Specifications. An operability determination was performed to assure operability. This restored compliance with Technical Specification 3.6.E.2.
Planned Actions to Prevent Recurrence
- 1) The immediate action taken is considered a short-term solution. The long-term plan is to implement a design change or continue administrative controls to assure ABSVZ boundary integrity.
- 2) As part of the corrective action, a review will be performed to ensure there are no other unaccounted for openings in the ABSVZ boundary. In addition, an assessment will be performed to identify if other configuration changes made during the pre-operational period may have unintentionally impacted the licensing or design basis of other systems. These actions will be performed as part of our corrective action process.
FAILED COMPONENT IDENTIFICATION None.
PREVIOUS SIMILAR EVENTS
None in the previous three (3) years.