What about NRC's focus to make their documents understandable to the common person. So here the NRC and the industry are jockeying for organizational advantage.
These guys have invented a language nobody can understand. Probably only a handful of people in the USA can understand. They are splitting a hair on a knat's ass to gain plant capacity factor with the possibility of both sides of the identical redundant component being degraded and broken at the same time.
They are turning engineering uncertainty into certainty. This is all special interest advantage dressed up as science, engineering and proof. They has been no actual testing of the system with this. It all guesswork.
Right, this is how corruption in industry is played out in our rotten political system. It goes on in all sides Dems and Reps. They jack up the complexity of the undecipherable regulation language so nobody on the outside can understand what is going on. In the stew of this self imposed language complexity, they get to choose what fragment of regulation framework the use for specific issue. It is similar to having no regulations at all and going on a whim. They give you the impression engineering stature based on science and facts...but it is all money greasing mindless deregulation for profit. They are chasing their tails finding money can be made off of it.
Right, and who profits the most from this. Its the politicians. It forces the politician to step in and settling these weasel words disputes without them even having a basic understanding how a nuke plant works. The genesis of all the too complex regulations and more knat's ass language hair splitting over regulation wording is money and stature to the politicians.
Even our common language is too imprecise, not complex enough, the penchant of humans to have different definitions for a word...to express the actual system hidden under the veil. There is a huge gap of knowledge of what we say we understand the system and what is the real system under the bullshit and money!!!
Description of Common Cause Failure Treatment in the TS Risk Informed Completion
Time (RICT) Program
The NRC proposed the TS Section 5.5 RICT Program be modified to address common cause
failure (CCF) as follows:
[d]. If a high degree of confidence cannot be established that there is no common cause
failure that could affect the redundant components, the RICT shall account for the
increased possibility of common cause failure. Accounting for the increased possibility of
common cause failure shall be accomplished by one of the two methods below. If one of
the two methods below is not used, the TS front stop shall not be exceeded.
• The RICT calculation shall be adjusted to numerically account for the increased
possibility of CCF, in accordance with RG 1.177, as specified in Section A-1.3.2.1 of
Appendix A of the RG. That is, when a component fails, the CCF probability for the
remaining redundant components shall be increased to represent the conditional
failure probability due to CCF of these components, in order to account for the
possibility that the first failure was caused by a CCF mechanism.
OR
• Prior to exceeding the front stop, RMAs shall be implemented. These RMAs
shall not already be credited in the RICT calculation, and shall target the success of
redundant and/or diverse SSCs that perform the function(s) of the failed SSC, and, if
possible, reduce the frequency of initiating events that call upon the function(s)
performed by the failed SSC. Documentation of the RMAs shall be available for
NRC review.
The industry proposes the following wording:
[d]. If the extent of condition evaluation for inoperable structures, systems, or components
(SSCs) is not complete, the RICT shall account for the increased possibility of common
cause failure (CCF) by either:
1. Numerically accounting for the increased possibility of CCF in the RICT calculation;
or
2. Prior to exceeding the Completion Time, Risk Management Actions (RMAs) [not
already credited in the RICT calculation] shall be implemented that support redundant
or diverse SSCs that perform the function(s) of the inoperable SSCs, or reduce the
frequency of initiating events that challenge the function(s) performed by the
inoperable SSCs.
Discussion of Differences
1. The format is revised to be consistent with the ISTS and the Writer's Guide, such as using
numbers instead of bullets and the appropriate format of the logical connector "or." See
TS Program 5.5.1 for an example.
Page 2 5/31/2017
2. (Paragraph d) The proposed term "high degree of confidence" has no objective measure
and will likely lead to inspection issues. One individual's high degree of confidence may
not align with another's. Instead, the industry proposes the objective measure of
completion of an extent of condition evaluation. If such an evaluation is complete, a
licensee and the NRC staff can consider common cause failure to be assessed. If not,
additional margin should be included in the RICT calculation.
3. (Paragraph d) The staff and industry proposals state that the increased possibility of a
CCF shall be accomplished by using one of two methods. The staff proposal then states
that if one of the two methods isn't used, a RICT can't be calculated (i.e., the front stop
cannot be exceeded). This statement is unnecessary. If one of the two methods must be
used and one is not used, a RICT can't be used.
4. (First bullet point) A TS Administrative Control Program description provides the highlevel
requirements for a licensee-controlled program that implements the requirements.
Note the TS RIC program introduction states, "The program shall include the following."
The TS program should include the requirements and constraints on the licensee's
program, but not every detail. The industry proposal simplifies the staff proposal in
several ways:
a. It is sufficient to state that the increased possibility of a CCF must be accounted
for numerically. In their review of licensee's implementation of TSTF-505, the
NRC may review the method used to numerically account for an increased
possibility of CCF. Methods other than that described in RG 1.177 may be
acceptable.
b. The following explanatory statement is removed, "That is, when a component
fails, the CCF probability for the remaining redundant components shall be
increased to represent the conditional failure probability due to CCF of these
components, in order to account for the possibility that the first failure was caused
by a CCF mechanism." Licensees understand the purpose of numerically
accounting for an increased possibility of common cause failure and this type of
explanation is not necessary or found in other TS Administrative Controls.
c. The reference to Regulatory Guide (RG) 1.177 is removed. Regulatory Guides
are not intended to be requirements. As stated on the front page of RG 1.177,
"Regulatory guides are not substitutes for regulations, and compliance with them
is not required. Methods and solutions that differ from those set forth in
regulatory guides will be deemed acceptable if they provide a basis for the
findings required for the issuance or continuance of a permit or license by the
Commission." As stated previously, the NRC staff may review the methods for
accounting for CCG as part of their review of the licensee's amendment request.
Page 3 5/31/2017
5. (Second bullet point) The term "front stop," while used in NEI 06-09, is not defined and
does not appear in the TS or Bases. Its use should be avoided in the TS. The paragraph is
revised to state "Prior to exceeding the Completion Time," which is equivalent.
6. (Second bullet point) The requirement, "These RMAs shall not already be credited in the
RICT calculation," is eliminated. At most sites, there will be proceduralized RMAs in
place for many situations. The PRA may credit some or all of these actions, but the
benefit from identifying an activity as an RMA is that it is performed, it emphasizes to
the plant operator its importance, and the RMA becomes a focus of the control room
while the RICT is in effect. For example, a plant’s protective actions may include
protecting the redundant (as opposed to diverse) train and by using a zero-maintenance
model some credit may be in the RICT calculation for this action. However, other
RMAs, such a stopping work in the switchyard or limiting transient combustibles near the
redundant train, reduce overall plant risk and are not specifically credited in the RICT
calculation. Even if there are no additional unique RMAs beyond those credited in the
PRA model, this increased focus enhances plant safety.
7. (Second bullet point) The proposed term "target the success of redundant and/or diverse
SSCs" is undefined and may be misinterpreted by licensees and NRC inspection staff.
The phrase "support the redundant or diverse SSCs" is more typical wording. Also, the
term "and/or" is avoided in the TS (See the Writer's Guide, section 3.1.1.h). A logical
"or" serves the same purpose as "or" is not exclusive.
8. (Second bullet point) The term "if possible" is typically not used in TS as the TS
represent legal requirements. Instead of stating, "and, if possible, reduce the frequency
of," the conjunction was rewritten as "or reduce the frequency of…". As stated
previously, a logical "or" is not exclusive and one or both actions may be taken.
9. (Second bullet point) The term "failed SSC" was revised "inoperable SSC" to be
consistent with TS terminology and the introductory paragraph d.
10. (Second bullet point) The statement "Documentation of the RMAs shall be available for
NRC review," is redundant and is eliminated. The TS program requires following NEI
06-09. Section 2.3.2, "Documentation," of NEI 06-09, step 6, states, "Relative to
extended CTs beyond the front-stop CT, the following shall be documented: … 6.5. Risk
management actions implemented." This requirement is reiterated in Section 3.1 of the
NRC's SE states (page 8), under "Documentation," which states: "Each entry into the
RMTS is required to be properly documented to permit proper review and oversight to
determine compliance with the TS requirements. The minimum requirements include: …
RMAs including compensatory actions implemented."
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