ML20090B501
| ML20090B501 | |
| Person / Time | |
|---|---|
| Site: | Ginna  |
| Issue date: | 05/11/1982 |
| From: | Nehemias J Office of Nuclear Reactor Regulation |
| To: | Holahan G Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML082380335 | List:
|
| References | |
| FOIA-91-106 NUDOCS 8205280441 | |
| Download: ML20090B501 (5) | |
Text
- - _ _ _ - _ _ - _ - _ _.
m
}
l
+
(
)! L
,i l
% z.44 D STRIBUTION:
W 11 1982
.GOCKET FILES RAB R/F FJCongel/ Plant File DNC N
MEMORANDUit FOR: Gary M. Holahan, leader
- f. a'Ecs Co Systems Section Operating Reactors Assessment Branen, Ot.
9 s
VPp0 5-FRON:
Jack V. hhusias
?
4,
% l Radiological Assessment Branch, OSI k%,'['y Radiation Protection Section 8
8Ssk 9,' y #
N anc sonu m m.ao) meu om OFFlClAL RECORD COPY usam.. m.
j
,c
('~
n
_ DRAFT For:
The Commissioners From:
William J. Dircks Executive Director for Operations
~ '
Subject:
ABNORMAL OCCURRENCE RECOMMENDATION - STEAM GENERATOR TUBE RUPTURE
~
(R. E. GINNA NUCLEAR POWER PLANT)
Purpose:
Approval of an abnonnal occurrence detenninstion.
_ Discussion:
Enclosed is a draft Federal Register notice describing 64 theer i
N rce.tha steam generator tube rupture event at the
& ** A ec. w ~,e a s c. -
R. E. Ginna nuclear power plant on January 25, 1982 TAmvent g
-Kt %, <M su m A w.l ce. it satisfies the criteria aw c.)t o e
or p.
prope'sd+4er reperting4 4:
major reduction in the degree of protection of the pub'lic health and safety. Example 11. A.2 ("For Commercial Nuclear
' Plants") of Appendix A of the Policy Statement on Abnonial Occurrence Reports (FRN, Vol. 42, No. 37,* 10950-52) notes that major degradation of the primary coolant pressure boundary can be considered an abnonnal occurrence.
T.he event involved the largest steam generator tube leak rate experienced to date. While the licensee's response was timely CONTACT:
l J. trooks/P Bobe t
492-4425/492-4426 l
C 2-and appropriately mit1 ated the consequences of the event such 9
that only miror radfological ef fects occurred, the event was complex and involved itens of safety concern such as the secondary NH-safety valve openings which provided an doisolatable pathway from the primary coolant system to the environment via the ruptured tube.
Recommendation:
That the Commission:
1.
Approve the subject-papesed abnonnal occurrence recom-mendationj together with its associated Federal Register w
Notice and 2.
Note that following approval, the Office of Congressional Affairs will notify the appropriate Congressional Committees of the intent to publish the Federal Register Notice.
Scheduling:
While no specific circumstances require Commission Action t
f 'd'-n by a particular date, it is desirable to dissemit *O V
abnonaal occurrence,(nformation to the public as sood iis y
( possible) Jt44#hpect$ that Commission action within e
two weeks of receipt of this draf t proposal would pennit publication in the Federal Register about ten days later.
William J. Dircks Executive Director for Operations
Enclosure:
Draf t Federal Register No tice
~
~
e-('
(7590-01]
-O NUCLEAR REGULATORY COMMISSION ABNORMAL OCCURRENCE STEAM GENERATOR TUBE RUPTURE (R. E. GINNA NUCLEAR POWER PLANT)
Section 208 of the Energy Reorganization Act of 1974, as amended, requires the NRC to disseminate information on abnormal occurrences (i.e., unscheduled inc.idents or events which the Commission detennines are significant frm the S" L5 standpoint of public health and safety). The.fM %.
incident was determined to be an abnonnal occurrence using the criteria published in the Federal Register on February 24,1977 (42 FR 10950). Example II. A.2 ("For Commercial Nuclear Power Plants") in Appendix A notes that major degradation of the primary coolant pressure boundary can be considered en abnonnal occurrence.
The following description of the incident also contains infonnation on the renedial actions planned and taken.
- - - Date and Place - The operating staff at the R. E. Ginna nuclear power plant notified the NRC Headquarters Operations Center at 9:33 a.m. on January 25, 1982 (via the Emergency Notification Systm phone) that the unit experienced a reactor trip from 100% power as 'a result of a steam generator tube rupture.
The R. E. Ginna unit is a Westinghouse-designed pressurized water reactor (PWR) owned by Rochester Gas and Electric Corporation (the licensee); it is
~
. located in Wayne County, New York.
Nature _and Probabic Consegu?nces - Steam generator tuhes in a pressurized water reactor are an integral part of the reactor coolant pressure boundary, keeping the. primary reactor coolant contained in a closed system and iselated frm the environment. The loss of integrity of steam generator tubes results in a breach of the primary-to-secondary system boundary.
~
('
d, 590-01]
e
'~
2-Safety margins include conservative design and administraf e controls during operation such that if a steam generator tube leaks, the leakage can en k sdh
- be detected r:pidly and the reactor w&idy shut down Periodic inspections a
r are also required to assure that degraded steam generator tubes are removed frm service.
When a tube is found to be degraded or leaking, integrity of the steam generator is restored by either plugging the tube at both ends or by a sleeving process. The repair reduces the likelihood of rapid leaks developing 4,lM orgof degraded tubes ee.b+h; which could result in adverse safety consequences l
3c~,c et should they fail in conjunction with certain postulated accidents.
In spite of p
these design and administrative controls,xthe complete rupture of a steam
&, L a c c ~ A % ~a.
~T % s generator tube can happen and is one of the design basis accidents considered in g
the NRC safety review of nuclear power plants.
Nuclear power plants are to have operational plans (procedures, trained ooeration and support personnel, and other capabilities) to cope with a cceplete rupture of a steam generator tube and mitigate any radiological consequences. The R. E. Ginna operating and support staff mitiga ted the consequences of the January 25 event such that the radiological consequences were insignificant in tems of risk from any resultant on-site or off-site ex po sures.
Seguence of Events 1/
A summary of the sequence of events for the steam generator tube rupture and the associated response actions follows:
i l
~1/
This summary was extracted from NUREG-0909, "NRC Report on the January 25, 1982 Steam Generator Tube Rupture at R. E. Ginna Nuclear Power Plant," April 1982.
.